Is Premium Grade Fuel More Efficient?

What is Gasoline?
Gasoline is made up of molecules made up of hydrogen and carbon atoms arranged in chains. Gasoline molecules have anywhere from, 7 to 11 carbon atoms in each chain. When you burn gasoline under STP, you get carbon dioxide. Which is from the carbon atoms   within the gasoline. A litre of Advance grade Gasoline contains about 1.3 x 108 joules of energy, which is equivalent to 123,000 BTU or 36,047 watt-hours. If it were possible for human beings to digest gasoline, a litre would contain about 31,070 food calories, the energy in a litre of gasoline is equivalent to the energy in about 130 McDonalds hamburgers.

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Where does gasoline come from?
Gasoline is made from crude oil which is drilled from the earth. This crude oil consists of organic material that has been decomposing over millions of thousands of years. The crude oil is then pumped out of the ground and is then refined to get different resources, Petroleum. Petroleum is a liquid that contains hydrocarbons which is used to make gasoline. All hydrocarbon molecules of different lengths have different properties. ex, a chain with just one carbon atom is, (CH4-Methane) it is the lightest chain. As the chains get longer, they get heavier. CH4 (methane), C2H6 (ethane), C3H8 (propane) and C4H10 (butane) are all gases, and they boil at -161, -88, -46 and -1 degrees F, (-107, -67, -43 and -18 degrees C). The chains C5H12 up through C18H32 are all liquids at STP, and the chains above C19 are all solids at STP. The different chain lengths have progressively higher boiling points, so they can be separated out by distillation. This is what happens in an oil refinery, crude oil is heated and the different chains are pulled out by their vaporization temperatures. The chains in the standard range are all very light and are easily vaporized and create clear liquids called naphthas. Dry, cleaning fluids can be made from these liquids, as well as paint solvents and other quick-drying products. The chains from C7H16 through C11H24 are blended together and used for gasoline. All of them vaporize at temperatures below the boiling point of water. That’s why if you spill gasoline on the ground it evaporates very quickly. Next is kerosene, in the C12 to C15 range, followed by diesel fuel C16 – C18 and heavier fuel oils (like heating oil for houses). Next come the lubricating oils. These oils no longer vaporize in any way at standard temperatures. For example, engine oil can run all day at 250 degrees F (121 degrees C) without vaporizing at all. Oils go from various viscosity from motor oil which is able to pass through the very high gear oils and then semi-solid greases. Vaseline falls in there as well. Chains above the C20 range form solids, starting with paraffin wax, then tar and finally asphaltic bitumen, which used to make asphalt roads. All of these different substances come from crude oil. The main difference is the length of the carbon chains.

What is Octane?
Almost all cars use four-­stroke gasoline engines. One of the strokes is the compression stroke, where the engine compresses a cylinder-full of air and gas into a much smaller volume before igniting it with a spark plug. The amount of compression is called the compression ratio of the engine. A typical engine might have a compression ratio of 8-to-1. The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like “regular” 87-octane gasoline) can handle the least amount of compression before igniting. The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine is to increase its compression ratio and the displacement of the engine. So a “high-performance engine” has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight, that is what makes the engine “high performance”, which means the engine is more efficient. The disadvantage is that the higher octane gasoline for your engine costs more. The name “octane” comes from when you take crude oil and “crack” it in a refinery, you end up getting hydrocarbon chains of different lengths. These different chain lengths can then be separated from each other and blended to form different fuels. For example, methane, propane and butane are all hydrocarbons. Methane has a single carbon atom. Propane has three carbon atoms chained together, etc. It turns out that heptane handles compression very poorly. Compress it just a little and it ignites spontaneously. Octane handles compression very well, you can compress it a lot and nothing happens. 87 octane gasoline is gasoline that contains 87-percent octane and 13-percent heptane (or some other combination of fuels that has the same performance of the 87/13 combination of octane/heptane). It spontaneously ignites at a given compression level, and can only be used in engines that do not exceed that compression ratio.
Table 1: Grades of fuel

Grade

Octane

% Ethanol

Carbon chain range

Density g/ml

Standard

87

10

C7H16 – C11H24

0.73

Advanced

89

5

C7H16 – C11H24

0.73

Premium

91

0

C7H16 – C11H24

0.73

Diesel

12

0

C16H34 – C18H38

0.84

Question: Is there value in buying higher grade fuel? Comparison of fuel grades using ∆H?
Hypothesis: Premium gas which has a higher octane rating will be more efficient than standard gas. Premium gas contains less ethanol, which has short chains, so has more longer chains which release more energy. 
Independent variable: Grades of fuel, Standard, Advanced, Premium ,and Diesel
Dependent variable: Temperature change
Other measured: Mass of fuel burned
Sample collections and plus transport:
Materials:

1 jerry can

Collection of fuel from gas station:
Method:
–          Clean and dry jerry can, starting from
–          Collect samples of fuel from gas stations
–          Transport to lab
–          Approximately measure 150ml of each fuel into a clean beaker.
Experiment
Materials:
●       Thermometer
●       Thermometer clamp
●       Stand
●       Spirit burner with wicks
●       Glass erlenmeyer flask
●       200ml Water
●       Clamp
●       Funnel
●       Lighter
●       Timer
●       Graduated cylinder
Method:

Pour approximately 150 ml of gasoline in a clean dry 250ml beaker.
Place ‘50 ml’ of fuel into clean, dry spirit burner in fume hood.
Weigh the filled fuel burner.
Measure and 200 cm3 of water into beaker.
Clamp beaker 15 cm above level ground.
Place thermometer in thermometer clamp.
Place thermometer in beaker and record initial temperature.
Place spirit burner under beaker plus light wick.
After 5 minutes record final temperature and extinguish flame.
Reweigh spirit burner.
Record data in table.
Repeat step 2-11, 9 more times with fuel sample.
Clean and dry spirit burner, let wick dry out.
Repeat steps 1-13 for other fuel samples.

Experimental results
Table 2: Experimental results and differences of mass and temperature

Grade of Fuel and trial number

Initial fuel mass(g)± 0.01

Final fuel mass(g)± 0.01

Initial temp(°C)
±0.5

Final temp(°C)
±0.5

Difference of mass (g)±0.02

Difference of temp (°C)±1

Standard #1

187.21

181.27

21

97

5.94

76

Standard #2

187.18

183.51

22

98

3.67

76

Standard #3

187.42

182.26

22

99

5.16

77

Standard #4

187.23

180.94

19

99

6.29

80

Standard #5

186.68

180.02

20

98

6.66

78

Standard #6

186.76

180.76

21

93

6

72

Standard #7

186.24

180.59

20

92

5.65

72

Standard #8

186.11

180.14

20

97

5.97

77

Standard #9

186.57

179.88

21

97

6.69

76

Standard #10

186.58

180.62

16

90

5.96

74

Advanced #1

184.62

179.7

25

88

4.92

63

Advanced #2

185.49

180.38

18

85

5.11

67

Advanced #3

184.58

178.6

18

87

5.98

69

Advanced #4

184.94

179.52

19

86

5.42

67

Advanced #5

185.29

180.23

17

88

5.06

71

Advanced #6

184.97

179.97

20

88

5

68

Advanced #7

185.37

180.9

20

88

4.47

68

Advanced #8

185.1

180.27

18

87

4.83

69

Advanced #9

185.01

180.1

18

88

4.91

70

Advanced #10

184.07

179.24

19

89

4.83

70

Premium #1

184.98

178.92

18

66

6.06

48

Premium #2

185.57

178.34

19

70

7.23

51

Premium #3

185.26

178.62

17

65

6.64

48

Premium #4

185.57

179.58

20

67

5.99

47

Premium #5

185.35

179.86

18

74

5.49

56

Premium #6

184.82

179.27

19

72

5.55

53

Premium #7

184.87

179.57

12

57

5.3

45

Premium #8

184.07

180.05

15

67

4.02

52

Premium #9

184.38

179.99

15

69

4.39

54

Premium #10

185.02

180.32

16

66

4.7

50

Diesel #1

192.85

187.67

21

54

5.18

33

Diesel #2

193.27

185.89

20

53

7.38

33

Diesel #3

192.92

186.25

22

57

6.67

35

Diesel #4

192.76

185.76

19

52

7

33

Diesel #5

193.17

185.99

18

49

7.18

31

Diesel #6

193.02

187.82

16

46

5.2

30

Diesel #7

193.32

187.52

19

51

5.8

32

Diesel #8

192.76

185.81

20

52

6.95

32

Diesel #9

192.98

186.99

22

60

5.99

38

Diesel #10

192.87

186.02

21

57

6.85

36

Analysis
To calculate q, we use q = M*c(constant)*∆T. Calculating heat change, q= the mass of water, 200 g, multiplied by the specific heat capacity of water multiplied by the change in temp. Then we calculate the heat change per 1 L .Finally we Average and % error for ∆H.
Calculating heat change in KJ
q =     m               c               ∆T
   = (200g)(4.18 J g-1 °C-1)(76°C)   
   = 90288 J / 1000
   = 90.288
Calculating heat change per litre
D = m/v  =>  v = m/D
            Standard #1    Density For gasoline             Diesel #1    Density for diesel
For gasoline: v =  5.94 g      /     0.73 g/mol                For Diesel:     5.18 g     /     0.84g/mol
Average Calculation
Add all V from above for each fuel and divide by 10, since there are 10 samples
(11096 + 11096 + 11242 + 11680+ 11388 + 10512 + 10512 + 11242 + 11096 + 10804) / 10 =11066.8 which is average heat change per liter.
Minimum calculation
Subtract average heat change by heat change of trial to get a positive or negative
11066.8 – 10512 = 554.8
Find largest negative number to get minimum calculation

Standard #6

6

72

86

8.2

10512

-554.8

Table 3: Calculation of heat change and heat change per Litre:

Grade of Fuel and trial number

Difference of mass (g)±0.02

Difference of temp (°C)±1

Heat Change(q) KJ

Change in Volume mL

heat change per L KJ/L

Standard #1

5.94

76

90

8.1

11096

Standard #2

3.67

76

56

5.0

11096

Standard #3

5.16

77

79

7.1

11242

Standard #4

6.29

80

101

8.6

11680

Standard #5

6.66

78

104

9.1

11388

Standard #6

6

72

86

8.2

10512

Standard #7

5.65

72

81

7.7

10512

Standard #8

5.97

77

92

8.2

11242

Standard #9

6.69

76

102

9.2

11096

Standard #10

5.96

74

88

8.2

10804

Advanced #1

4.92

63

62

6.7

9198

Advanced #2

5.11

67

68

7.0

9782

Advanced #3

5.98

69

83

8.2

10074

Advanced #4

5.42

67

73

7.4

9782

Advanced #5

5.06

71

72

6.9

10366

Advanced #6

5

68

68

6.8

9928

Advanced #7

4.47

68

61

6.1

9928

Advanced #8

4.83

69

67

6.6

10074

Advanced #9

4.91

70

69

6.7

10220

Advanced #10

4.83

70

68

6.6

10220

Premium #1

6.06

48

58

8.3

7008

Premium #2

7.23

51

74

9.9

7446

Premium #3

6.64

48

64

9.1

7008

Premium #4

5.99

47

56

8.2

6862

Premium #5

5.49

56

61

7.5

8176

Premium #6

5.55

53

59

7.6

7738

Premium #7

5.3

45

48

7.3

6570

Premium #8

4.02

52

42

5.5

7592

Premium #9

4.39

54

47

6.0

7884

Premium #10

4.7

50

47

6.4

7300

Diesel #1

5.18

33

34

6.2

5544

Diesel #2

7.38

33

49

8.8

5544

Diesel #3

6.67

35

47

7.9

5880

Diesel #4

7

33

46

8.3

5544

Diesel #5

7.18

31

45

8.5

5208

Diesel #6

5.2

30

31

6.2

5040

Diesel #7

5.8

32

37

6.9

5376

Diesel #8

6.95

32

44

8.3

5376

Diesel #9

5.99

38

46

7.1

6384

Diesel #10

6.85

36

49

8.2

6048

Graph 1: Average heat change per litre of 4 different grades of fuel:
 

Table 4: Average change of heat per Litre and maximum and minimum values

Grade of Fuel

Average heat change per litre

Max heat change per Litre

Min heat change per Litre

Standard

11066.8

11680

10512

Advanced

9957.2

10366

9198

Premium

7358.4

8176

6570

Diesel

5594.4

6384

5040

 
Conclusion
Premium gas which has a higher octane rating will be more efficient than standard gas. Premium gas contains less ethanol, which has short chains, so has more longer chains which release more energy. This hypothesis is incorrect since the efficiency of an engine is not measured by the fuel used. There are many other factors that make a engine run efficiently instead of the fuel, such as compression ratio, displacement, speed of engine size of cylinder and many other factors. The experimental data shows that the highest energy change per litre occurs in standard fuel and there is a downward trend towards diesel. This is clearly shown in graph 1. The amount of ethanol in the fuels may be affecting the comparison of each grade of fuel. It’s possible to calculate the energy coming from ethanol and then compare the grades of fuel based on their octane rating. This was not what was expected as premium gas was expected to be the most efficient since it has the highest amount of longer carbon chains. The graph represents a linear slope which is within the errors, so this graph shows my accuracy and precision with the lab.
As i proceed the lab i learned that the fume hood was causing my flame to become unstable and shift at random. This is a big error since the flame did not constantly heat up the erlenmeyer flask through the allotted time. Another source of error could be the wick, since it had to be left soaking the fuel to be fully absorbed into the fibers to allow proper combustion to occur. The 50 ml of fuel was then poured into the spirit burner to after the wick was fully soaked to make sure there was no extra fuel being soaked by the wick. Furthermore, if deionized water was used in this experiment the sources of error could be further reduced since the chances of impurities in the deionized water would be very low. Also, I would use my time more efficiently by preparing the next set of trials as the experiment was taking place since 5 minutes of standing around and doing nothing would be a waste of time, when i could be filling up my beaker with water to carry out my next results. If i was given the chance to carry out my experiment one again I would make some minor adjustments, for example, i would use  erlenmeyer flasks instead of one, since it took a long time to clean and fill up. I could quickly switch the heated erlimyer flask for the fresh one to carry out the rest of my experiment and before i walk away to clean the used flask i would start my next trial.
References

https://www.ocean.washington.edu/courses/envir215/energynumbers.pdf
https://www.quora.com/How-much-energy-is-released-by-burning-1-litre-of-petrol
https://iet.jrc.ec.europa.eu/about-jec/sites/iet.jrc.ec.europa.eu.about-jec/files/documents/report_2014/wtt_appendix_1_v4a.pdf
https://www.rapidtables.com/convert/energy/Joule_to_Calorie.html
https://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/gas-price.htm
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=272881
https://afdc.energy.gov/fuels/fuel_comparison_chart.pdf
http://chemed.chem.purdue.edu/genchem/topicreview/bp/1organic/coal.html
https://www.pacelabs.com/environmental-services/energy-services-forensics/forensics-101-a-primer/identifying-hydrocarbons.html

 

Amaca Premium Economy Seat

Amaca Premium Economy Seat

Interim Report

Table of Contents

Acknowledgement

Airline Premium Economy Seat: An Introduction

Project Aims and Objectives

Aim

Objectives

Challenges in Flying

Cabin Environment Induced

Seat Induced

Market Average Premium Economy Seat Production

Characteristic

Market Size

Sections with Room for Improvement

Passenger Perspective

Airline or Carrier Perspective

Seat Wise

Legal Regulations for Passenger Safety

Tests

Federal Aviation Regulations (FAR) Dynamic Testing for Transport Category Aeroplane

Amaca Airline Seat

Introduction

Unique Selling Proposition

Planning

Aims and Objectives Action Plan

Gantt Chart

References

The concept of Premium Economy seat all started in the mid-80s when Sir Richard Branson, founder of the Virgin Group, made a game-changing plan of offering sleeper-style seats to business class passengers in place of the then-standard recliners in his start-up line Virgin Atlantic. With Virgin Atlantic now having an improved edge in product quality, other airline giants gradually morphed their older business class cabins with seats that could recline up to 170 degrees or so, at an angle to the floor.

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With the persisting development of lavishness for business class, and therefore growing fares, the fare gap between business and the steadily worsening “main cabin” economy continued to widen. It was in 1991 when EVA Air in Taiwan then decided to bridge the gap with premium economy. Virgin Atlantic followed suit in 1992, with European and Pacific long-haul airlines gradually offering the service, as well [4].

Now, there are 27 airlines with premium seats in operation [5].

Premium Economy seats are not standardised and vary widely from airline to airline. Current premium economy remains very much as it was when EVA Air started it. It serves almost exclusively for the long-haul, wide-body aircraft [4]. Target consumers for this service are primarily comfort-seeking leisure passengers and price sensitive business consumers. The seat’s unique proposition ranks itself midway between business and economy class with enhanced legroom as its principal attribute. Other advantages include, but not limited to: increased seat width; more seat recline angle; additional Frequent Flyer points to some airlines; additional baggage allowance; prioritised boarding; dedicated check-in counters; heightened in-flight entertainment with better quality screens; power ports for laptop charging; broader meal variety; separate toilets from economy flyers; welcome drinks and amenity kits [5].

As a result of increased demand for long-haul travel and a growing number of consumers, it was not long for premium economy class to have gained a secure foothold in the aviation industry. Although considered a success, the concept of Premium Economy remains in a formative stage with a room for innovative growth and improvement.

This year’s assigned individual project is about a premium economy seat product currently being developed by Tom Johnson Design UK, who is working on “a solution to an increasing disparity between passengers, who want greater comfort, and airlines who need to maximise profit per unit of cabin area” (Johnson, 2017).

Aim

To develop a more competitive premium economic seat.

Objectives

Listed below are the research’s main objectives that will serve as a guideline for the next four months of continued research.

It is the objective of the research to:

Optimise current structural design

Reduce the weight of the seat, all the while maintaining the structural integrity by running a mock static testing on the seat adhering certification standards through computer analysis.

Ensure safety of passenger by running mock dynamic testing on the seat adhering certification standards through computer analysis.

Fabricate a scale model of the assembly using 3D printing.

Prototyping incites design iterations and development testing. The tool is also beneficial for communicating and when collaborating during the early stages of the seat’s design process. It is essential in the optimisation of the design. Through a quick turnaround, the prototype reduces the risk associated with novel designs in meeting all its requirements upon its initial release and avoid costly issues that arise during manufacturing, assembly and the early service life of the seat by spotting them and necessitating changes right away [23]. 

         2.1 Make use of CNC machines or other forming and fabricating techniques available in the university.

Cabin Environment Induced

The aircraft cabin is comparable to any other indoor settings, such as homes, offices, in that occupants are exposed to a mixture of outside and recirculated air. Supplied outside air or bleed air on aircraft cabins are usually by a compressor on the engine [2]. What differentiates aircraft cabins in many aspects – for example, is higher occupant and air tightness density, the inability of occupants to leave at will, reduced air pressurisation, low humidity, and potential exposure to contaminants such as ozone (O3), carbon monoxide (CO), various chemical and biological agents [2], [3]. Polluted air is harmful to health, and the risk towards the occupant increases as constrained spaces pose more concern compared when in the open atmosphere.

When aircraft fly at high altitude, (commercial aircraft fly at between 25 000ft and 41 000ft) the cabin pressure is reduced to ease stress on the fuselage. There are loads of occupant discomfort associated with lower cabin pressure. Held accountable for the “popping” situation in the occupant’s ears before take-off and landing is the drop and increase of cabin pressure. Decreased cabin pressure also results in lower oxygen and moisture content in the cabin environment, causing fatigue, dehydration, and potentially increasing the risk of deep vein thromboses.

Seat Induced

Comfort is not simply the absence of discomfort, and indeed both can occur at the same time.

One of the essential factors influencing aircraft seating comfort in all classes is legroom. Other than legroom, back support and head support were amongst the factors that are always rated by surveyed passengers as important. Seat pitch influences the available space and legroom for the occupants. Seat pitch is the technical term used by airlines and refers to the distance between the back of your seat and the seat in front of you [7]. The depth and the contour of the backrest reduce the available legroom.

Clearance, width, and seat pitch is what we identify as comfort measures, and from this, we can conclude that maximum comfort correlates to maximum values of the comfort measures.

Most seat related comfort issues arise out of economy class travel.

The current minimum spacing and design standards for transport-category aircraft allow far too-tight seating, especially on airlines which feature a higher density of economy seats per cabin [8]. Congested space brings a lack of legroom, lack of personal space, sore back, cramped legs, narrow space and lack of recline. However, some of these complaints extend into premium classes too, where the additional cost of tickets brings an increased tendency for occupants to find faults with their travel.

Complaints in premium economy are often similar to those in the economy class. Lack of legroom- particularly for stretching. So although the seat pitch fits the knees, space to stretch out when the occupant wishes to recline is limited. Recline and legroom that don’t meet passenger expectations of higher-cost seats seem to come up often, as does seat comfort when trying to sleep.

What is offered by airlines for what they consider premium economy can differ quite considerably, and it can be hard to know what to expect. Seat wise, as shown in Figure 1, the average marketed premium economy seat weighs approximately 24kg. The seat reclines to a 120-degree angle, and the maximum seat pitch you can get is 39″ or 990mm.

General seat features when booking a premium economy class include additional legroom, extra inches of recline ability, power outlets and a bigger personal entertainment screen [9].

The price difference compared to an economy class depends on the airline and the route you’re flying. Most airlines are exceptionally coy about how much they charge for the premium economy class. However, Air New Zealand says premium economy fares are about 30% higher than normal economy fares [10]. Other airlines follow this rule while some also double the cost of an economy class ticket. Companies charge tickets considering the current supply and demand, so there is no set formula to determine what price you can expect to pay.

Market Size

The International Air Transport Association (IATA) expects 7.2billion passengers to travel in 2035, nearly doubling of the 3.8billion air travellers in 2016 [22]. This prediction is based on a 3.7% annual Compound Average Growth Rate (CAGR) noted on the 20-Year Passenger Forecast, an analysed report by IATA identifying major traffic trends for the next 20 years.

According to Transparency Market Research, a 12.9% growth of CAGR during the forecast period 2017-2016 is expected in the global air seating market. It further in states that more than $27.5billion worth of aircraft seats are to be sold globally by the end of 2026 [22].

The precise amount of economy seats in operation today is not easy to discover. The airline seat industry’s secretive nature and the difficulty of identifying what constitutes as ‘premium economy’ adds to the challenge of identifying the seat’s volume in the market.

Tom Johnson, designer and developer of Amaca Premium Seats, approached the question of the premium economy’s share within the seat market by building a spreadsheet of long-haul airline fleets, their various aircraft types and the mix of seating classes for each of their aircraft.

The Market Research he conducted sampled United Airlines, British Airways, American Airways, Cathay Pacific, Lufthansa, Air China, Delta Airlines, Air New Zealand, ANA, Air France, Thomas Cook, Singapore Airlines and Qantas.

In his market research, he found out that 14.2% of the long-haul seats offered, and soon-to-be-filled orders from the sampled groups are premium economy.  This share is expected to grow, however, with recent Airbus A350 orders for Singapore Airlines.

At $10,000 per premium economy seat, that 14.2% would represent a potential market of almost $10 000 000 per year. We also must consider that airlines do not replace their cabin seats every year as an aircraft seats average life spans to seven years.

Approaching it another way, the 14.2% of the total seat sales of $4.6billion in 2016 is $650million. However, this figure is susceptible to error because short-haul aircraft, which makes up 75%-80% of the global airliner economy fleet) often have no premium seats at all.

The closest estimate could be through discounting the overall short-haul aircraft entirely, which reduces global seat sales to 20% of $4.6billion ($920million) and then take 14.2% of the figure. So, we are looking at a global market share of $130million for premium seats.

Passenger Perspective

From a passenger perspective, the list of desirable changes is almost infinite. The ultimate expression of what they expect would be a first class product that would not consequence to paying loads. The most common complaint that would come up in the premium economy experience is that the marketing images of the seats are often exaggerated compared to space available in their real product. Often, passengers seated in front would recline into their face, despite the advertised greater pitch. The aft-seated passenger will then have a reduced space, as showcased in Figure 1. This source of irritation can also cause, for example, spilt food and drink, the inability of the inboard seated aft passengers egress and ingress, and the inability for the aft-seated passenger to use the meal tray [11].

Airline or Carrier Perspective

Airlines have lots of choices when they order seats for their airplanes. Those selections go a long way to determining how comfortable – or uncomfortable – their customers will be. However, airlines are known to be extremely parsimonious [12]. This can sometimes affect the level of comfort their service can provide towards the passengers.

From the airline perspective, the ultimate product would be ultra-dense seating where passengers would be willing to cash in extra money. Realistically, however, some compromise and common sense are necessary. Consequently, when speaking of premium economy seat specifically, airlines incessantly require from manufacturers denser, lighter seats that keep the premium experience (and hence perceived value by the passengers).

Seat Wise

 

“You get hot spots on the back of your thighs. You’re in misery but you don’t know why,” Robert Funk, Vice President for sales and marketing for the seating division of Zodiac Aerospace.

One of the most crucial elements for seat comfort, and is most carefully studied, would be the seat bottom. The principle is that the longer it is, the better, as they offer better support for the occupant’s thighs. Manufacturers, however, are most of the time ordered reduced seat length as to save space and money.

Another area of the seat which can be improved is the leg rests to increase blood flow and take the strain off muscles. Furthermore, the height of the seat off the floor is also a factor for comfort. The standard height would be around 18″, but some European airlines with generally taller passengers would want seats constructed higher, as so to stop the legs from resting in an awkward angle.

Alex Pozzi, Vice President of Technology and Seating Development at Rockwell Collin’s seat manufacturing division, disclosed that airlines have their long-held prejudice on seats. Some prefer a firm cushion. Others want it to be softer. Even when the manufacturers put forward one particular firmness that the company thinks would provide ideal support and comfort for most passengers, some airlines persist on modifications using own preference. “There’s some science there and some not-so-much science”.

Factors that needs prioritising when designing should be how the geometry of the seat could improve seat recline, foot space and privacy as these are the essential aspects of what premium economy should bring to passengers.

Another significant issue for the airlines’ business that is becoming an increasingly important consideration in the design of seats is the weight. Seats are in the cabin for the life of the aircraft contributing to fuel consumption.

From a technical perspective, aircraft seats are the skeletal interference between the aircraft and the passenger. For that reason, it is one of the most influential components on the safety of the flight of the passengers [14].

It doesn’t matter how many passengers the airline may want to crowd the aircraft, cabin capacity has its limits. The structure of the passenger seats gets influenced by requirements such as certification which prove that any aircraft, within 90 seconds, can be vacated in the event of an emergency [15].

Each feature of the cabin components embedded inside the aircraft must conform to stringent regulations governing their properties, such as for fire conduction and corresponding toxic emissions.

A lot of these regulatory improvements are born out of lessons learned back when aircraft accidents – crashing and cabin incidents – were far more prevalent than it is today. During the Golden Age of flying, there are loads of aircraft that did not meet any of the regulations we have available now, and which, to those accustomed with the physics and dynamics of the current standard regulations,  seem outrageous, though it is because of the lack of risk knowledge – with tragic results that such as death[16].

As a result, we prioritise details of the design of the aircraft cabin with restrictions of necessary and prioritised safety over aesthetics. In conclusion, judging cabin should not only consider the appearance but take into account how these components overcome the challenges of safety requirements, all the while providing a growing variety of comfort features. 

Tests

Seat requirements leave seat designers and manufacturers limited freedom to fulfil the legal requirements of crash safety.

When it comes to flight safety, the Federal Aviation Administration (FAA) and its European counterpart, the European Aviation Safety Agency (EASA) are the administrations concerned with the regulations issued. To generate uniformed standard requirements in aviation between the US and Europe, the Certification Specifications (CS) and the Federal Aviation Regulation (FAR) are to some extent agreeing content-wise.

The entire list of technical requirements for the developers of aircraft, and hence, the seat developers and component suppliers, is stated in the airworthiness paragraphs, which are in Part 25 (CS/FAR-25). For seat certification, TSO C127A is the current valid reference documents. This document, in turn, refers to the SAE AS 8049A (Performing Standard for Seats in Civil Rotorcraft, Transport Aircraft and General Aviation Aircraft), which specify the minimum requirements for a seat to be approved.

The tests involve dynamic and static tests, including 14G and 16G (crash) tests and the Head Impact Criterion (HIC) test. Flammability Testing is also conducted on all the components of the seat, the mentioned evacuation assessment, and bone loading tests.

Federal Aviation Regulations (FAR) Dynamic Testing for Transport Category Aeroplane

The information below provided by Advisory Circle (AC), lays down an introduction of the guidance concerning adequate, but not the only, means of compliance with Part 25 of the FAR relevant to dynamic testing of seats [16].

 To evaluate the aeroplane seats, its restraints, and related interior systems to showcase seats’ ability and structural strength when it comes to protecting the passenger from injuries during a crash environment.

The Tests’ Standard Procedures – Reasons and Practices

The tests defined in Part 25 are standardised practices that are usually procedures to be considered as the minimum necessary to confirm compliance. Such standardised procedures guarantee that, to the maximum measure possible, rules consistency remains between different facilities.

Standard Test Procedure – Relationship to Design Standards

As mentioned before, a standardised test is necessary. The most apparent examples are the size and the weight representation of the passenger and the two discrete directions specified for the test impact. Although the theory is no different than the static test, testing and results are much more complex.

Introduction

Figure 2 Amaca Logo

Developed by Tom Johnson Design UK, which is an innovation & development consultancy, Amaca Airline Seat is a concept design which brings novelty for premium economy airline seating. Tom Johnson, who is a multi-disciplinary designer and inventor, has been working on this projects since early 2013. It is currently patent pending, with work beginning on early stage prototype [13].

Unique Selling Proposition

Figure 3 Amaca’s Premium Seat Design Response

The seat weighs 20% less than the average marketed premium seats.

The seat reclines 9.6% more than the average marketed premium seats.

Pitch: 35”

Foot space obstruction reduced and the design maximises the space given.

Issues with recline ability regarding the loss of personal space for the aft-seated passenger and the loss of privacy for the reclined passenger (due to exposed face) eliminated, as can be shown when comparing Figure one and Figure 3.

Modifying the cabin is unnecessary during instalment.

Aims and Objectives Action Plan

Listed below the bullet pointed project objectives are the steps of strategies and plans that needs initiating to achieve success on this research.

In order to:

Reduce the weight of the seat, all the while maintaining the structural integrity.

A computational investigation should be done examining the properties of materials used in the construction of the seat assembly.

Venture on and investigate properties of other structural materials.

Apply studied materials into the seat assembly and record results.

Attempt changing the geometry of the parts of the seat structure.

Optimise current structural design.

A computational investigation should be done examining the properties of the components and how a different design variable can improve dynamic characteristics.

There should be a limit when trying to change the structure or the mechanism of the seat for comfort. When going overboard with modification, the design could probably lose if something becomes heavier or it becomes too costly [19].

Run mock dynamic testing on the seat adhering certification standards through computer analysis.

Seating system prepared for the model should include the seat’s main structure, bottom and back cushions, a three-point restraint and an FE 50th percentile Hybrid III dummy model [18]

Analyse with care to solve the system in such a way that it ensures accuracy and it does not mask any prominent physical behaviour of the system.

The analysis should put into thought the FE modelling of seat structural and non-structural components, boundary conditions. The output should be discussed and analysed.

For the test relating to floor deformation in emergency landing situation:

The structure on the seat must resist impact. In the scenario created, a sudden deceleration of 16 g should be applied to the seat and the dummy, which will be moving at a given velocity. To simulate the worst-case scenario, the floor should be deliberately deformed prior to applying deceleration [17].

Figure 4 16G Impact Analysis Simulating an Emergency Landing

Perform a lumbar dynamic test that will measure the sturdiness of the seat. The test analysis should include seat pitch angle, velocity, seat yaw angle, peak deceleration, time-to-peak and the floor deformation. As a boundary condition, a 60° angle load should be applied to represent the load in an emergency landing of an aircraft with no wheels and a 14 g deceleration [17].

Run mock static testing on the seat adhering certification standards through computer analysis.

Run static tension test for every part of the seat assembly [20].

Perform virtual static testing to evaluate the strength of the seat legs and their connection to the floor.

Virtual body blocks, which serves as a representation of the passenger sitting on the seats, are secured on the basic seat frame, and static loads are applied up, down, fore and aft directions [17].

Review the analysis results to ensure that the base of the seat frame remains intact.

Fabricate a scale model of the assembly using 3D printing.

If available, CNC machining, metal stamping, and other metal or plastic forming and fabricating techniques are used during this phase.

[1] Johnson, T., (2017), Product Information, Amaca Premium Seats, [Accessed: 25 October 2018]

[2] National Research Council (US) Committee on Air Quality in Passenger Cabins of Commercial Aircraft. The Airliner Cabin Environment and the Health of Passengers and Crew. Washington (DC): National Academies Press (US); 2002. 1, Introduction.Available from: https://www.ncbi.nlm.nih.gov/books/NBK207483/

[3] Zuber, M, Ahmad, K & Riazuddin, V. (2014). A Review on the Impact of Aircraft Cabin Air Quality and Cabin Pressure on Human Wellbeing. Applied Mechanics and Materials. 629. 388-394.

[4] Perkins, M (2017), The Future of Premium Economy Seating Is Now, [Accessed: 15 November 2018]

[5] Hugan-Duprat, C., O’Connell, J., (2015), The rationale for implementing a premium economy class in the long haul market – Evidence from Transatlantic market, Journal of Air Transport Management, Volume 47, Pages 11-19

[6] Kremser, F., Guenzkofer, F., (2012), Aircraft seating comfort; the influence of seat pitch on passenger’s well-being, Volume 41, Pages 4936-4942

[7] Walton, J., (2012), Leg room seat pitch, your personal space on an aircraft explained, [Accessed: 30October 2018], Available from: https://www.ausbt.com.au/leg-room-seat-pitch-your-personal-space-on-an-aircraft-explained

[8] Cramped Seating Can ‘Trap’ and ‘Trip’ Passengers During Emergency Evacuation. 2001. Air Safety Week, Volume 15, Issue 42, pp. 1.

[9] Choi, B., (2018), Premium Economy vs Economy – What’s the difference?, [Accessed: 30October 2018], Available from: https://www.skyscanner.com/tips-and-inspiration/premium-economy

[10] Conway, B., (2007), A cut above; is premium economy about to become more widespread? Flight Airlines business, [Accessed: 30 November 2018], Available from: https://flightglobal.com/news/articles/a-cut-above-is-premium-economy-about-to-become-more-220283/

[11] Beroth, M., (2004) Aircraft Sleeper Seat. Patent No.: US 6 692 069 B2

[12] Mccartney, S., 2018, Life & Arts — The Middle Seat: The Secrets of Airline Seats — The little design choices carriers make — sometimes just an extra inch — can mean everything on a long flight. Wall Street Journal. ISSN 00999660.

[13] TOM JOHNSON DESIGN, (2017), Amaca, [Accessed: 30th October 2018], http://tomjdesign.com/>

[14] Olschinka, C., Schumacher, A., (2006), Dynamic Simulation of the Flight Passenger Seats

[15] Garcia, M., (2014), The Future of the Aircraft Cabin, Tracking Trends and Debunking Myths, Report no.: 23, Pages 1-35

[16] Federal Aviation Administration, (1995), Transport Airline and Engine Issue Area Seat Testing Harmonization Working Group, Vol. 57, No. 239

[17] Caileteau, J., (2009), Airline Seat Testing Soars to New Heights, Concept to reality, [Available on: www.altair.com/c2r]

[18] Bhonge, P., (2008), A Methodology For Aircraft Seat Certification by Dynamic Finite Element Analysis

[19] Sumers, B., (2017), Designing and Airline Seat From Scratch is Not as Easy as It Looks, [Available on: www.skift.com]

[20] Bhonge S., Hamid P. & L., (2011). Fine-tuning Nonlinear Finite Element Analysis Methodology for Aircraft Seat Certification using Component Level Testing and Validation. International Journal of Vehicle Structures and Systems. Volume 3

[21] Jiang, W., Vlahopoulos, N., Castanier, M., (2015), Turning material and component properties to reduce weight and increase blast worthiness of a notional V-hull structure, Case Studies in Mechanical Systems and Signal Processing, Volume 2, Pages 19-28

[22] Aircraft Seating Market- Global Industry Analysis, Size, Share, Growth Trends and Forecast 2017-2026

[23] Steward, T., Bibb, R. Millward, H., Rapid Manufacturing for Premium Aircraft Seating