A very proper British fellow named Frank Whittle invented what powers nearly all modern aircraft today in 2023. He wrecked 3 aircraft while training to fly as a cadet early on. While learning to fly he first wrote a thesis & concentrated on engines, connecting speed, range & engine efficiency, so if you wanted to go fast & far you would have to go very high in the atmosphere, around 50,000 ft elevation, where piston engines that at that time dominated small blade propeller driven early aircraft that struggled to reach 150 mph, using car motors on a bigger scale with many moving parts. Even though you can supercharge the engine, eventually there comes a point where the engine cannot even overcome its internal friction, in the thin air of the upper atmosphere.
I can't think of at least 300 ways to improve Turbofan engines with existing technologies, like chemical vapor deposition, advanced ceramics, super conducting electric motors, energy recovery, thermal recuperation, texturing surfaces to reduce drag & turbulence of smooth airflow in the engine or deliberately introduce tumbling & better mixing in the combustion section, to block heat from damaging the exhaust turbine, to enhance thermal efficiency, reduce fuel consumption, reduce toxic emissions, reduce noice, vibration & harshness with ceramic axels & bearings, magnetic bearings, helium bearings & many other ways to use new polymers, ceramic hybrids, metalloids, emergent graphene & electric high strength magnet motor alternators & more to make hybrid electric passenger aircraft engines that are way better in every way! Throughout this posting I share some of these ideas openly hoping they're will reach engine manufacturers!
Frank thought of increasing compression & replacing the piston with a turbine, substitute a turbine engine for the piston engine. With only 1 moving part, a shaft with a compressor driven by an exhaust turbine at the opposite end of the shaft, fundamentally simple & with refinements over time, turbine aircraft engines would become more durable in terms of operating life between services & overhauls, than even the best diesel engines, which is amazing. We are talking about 20,000 hours of operation between servicing, about 20x better than the best diesel engines.
The newest have higher bypass ratios, higher thermal efficiency, better fuel economy, lower emissions, better performance per unit of mass, improved aerodynamics, greatly improved peak power output, longer service intervals, innovative blade geometry & many other improvements in the shaft bearings, interior geometry, compression optimization, fuel burn optimization, exhaust heat energy rejection TBC coasting to enhance the high nickel super alloy blade operating life, an emergent catalytic coatings of the exhaust blades, texturing of the turbine blades, texturing of the combustion burner chamber walls, texturing of the interior surfaces, force air cooling in the engine jacket, and very high bypass ratios so that a small power core turbine can turn a very large intake fan that produces a lot of thrust around the core, reducing noise & emissions thereby also. The GE Gen. X aircraft engines feature a lot of this emerging technology!
Watch this cool documentary https://youtu.be/G0T4-XG612Q
Frank Whittle was only 22 years old when he had the genius idea of a jet engine, making use of all the hot exhaust gas to produce propulsion energy, while also recovering some of the hot expanding mixture of fuel & air combusting to rotate the exhaust turbine blades that impart mechanical rotation torque on the shaft connected to the front compressor blades, thus forming a continual stream combustion device, unlike the highly pulsatile nature of limited piston engines that were unable to drive aircraft to higher velocities, especially at higher elevations where the oxygen concentrations of air much lower than the high O2 content air than near ocean level, where the partial pressure of oxygen higher & results in a rough air content of ~21% O2.
The driving concepts behind the jet engine development were smoothness, less vibration, & better laminar exhaust flow than anything a piston engine could create. So lower NVH, better smoothness, less noise, more elegant & more refined. Jet engine was the result of pursuing a more excellent way to power aircraft with combustion. Turbine engines leverage the power of wheels & axels, which has been used on land vehicle, carts, chariots & other wheeled vehicles for millennia.
The early development of the jet engine was remarkable underfunded, even though it would go into Britains first jet aircraft. They were forced to re-use parts that should have been scrapped for recycling.
By 1944 the efficiency of jet turbines was so low, giving poor range, especially at modest speeds, that a turbofan engine was being developed by Whittle' & his team. This higher bypass turbine aero engines are the predecessor to all modern passenger aircraft engines, produced by the thousand worldwide for airlines that service flight passengers at airports around the world.
The turban engine empowered the Jet age & airfare prices started declining to democratized price levels making flight a travel option for more people! This kicked off globalization at a faster rate, enabling people to get nearly anywhere on earth within about 1 day. Ships making similar global journeys for passengers took weeks or months by comparison. Jet engines & then turbofan engines enabled fuel efficient passenger aircraft like the Boeing 727, 737, 747, 767, 777, 787 etc to be energized by turbofan technology that is still being refined to improve efficiency & reduce emissions of toxic fumes or poisonous exhaust gas components, even through the majority of combustion products consist of CO2 & water vapor, its the trace pollutants in exhaust gases that are toxic to human & environmental health. Turbo-fan with bypass enabled thermal efficiency to rise to 75+ %, extracting more of the fuels chemical energy to produce thrust to move the aircraft, its cargo, passengers, weapons or whatever. Most importantly, power jets enables 1000 mph flight!
Frank helped to make the world a smaller place by enabling nearly anyone to fly on a passenger aircraft anywhere in the world. Sometimes in remote areas, it requires connecting flights, layovers, riding in a turbo-prop airplane, riding in a puddle jumper, a smaller jet, military transport, or similar unconventional aircraft. Winter storms shut down air-travel, something that Christmas 2022 travelers had a difficulty with as the east coast of the USA hit with record breaking snow blizzards & similar. The airlines lost peoples luggage in a debacle so intense that Southwest under criminal investigation.
Speaking of a crime, it's a crime that Frank was denied credit for his pioneering work on jet engines, turbo fan & turbo prop engines that revolutionize air travel & military aircraft helping the allies win WWII. He was a genius who simplified engine designs by making a single moving part able to shove out tremendous thrust continually, all while spinning at amazingly fast RPM's, over 100,000 RPM. It took the development of amazing super high temperature creep resistant metal alloys, computer aided engineering, test stand optimization & many other applied technologies & special techniques in manufacturing to make todays amazing aircraft engines.
Hobby Turbine Engines are trendy on YouTube, the hog fuel, have 25 hour bearing life, spin at over 100k rpms, emit deafening noise levels, inhale expensive oil in the fuel that costs $27 per gallon, have to have expensive auxiliary electrical fueling systems & controllers and end up costing thousands of dollars for output you can get from an 8kw piston engine for 1/20th the cost & only a tiny net weight penalty by comparison, in a mass optimized generator set // with less maintenance & significantly lower operating cost. Its not until you get to the 30kw range CHP setups for large homes & medium sizes commercial buildings where the heat can make warm air, hot water & the electrical power generated can be used by loads, so a smaller or medium sized brewery or distillery might be ideal for such a system from Capstone Micro-turbine CHP solutions that can use high pressure natural gas supply or bio-waste gas recovery from composting the biological waste from the brewing or distilling. A artisan bakery or glass studio can use a CHP setup to make waste heat for the ovens, kilns, glass furnace, while also making electricity for, lighting, HVAC & other electrical loads like computers, bitcoin mining rigs ASIC setups or similar, rack servers or similar, especially the conversion of water into cryogenically cooled liquid hydrogen & liquid oxygen that can be sold commercially, made with electrolyte spiked water, even waste water from cleaning or rinsing the equipment, hydrogen that can be sold for use in fuel cell electric vehicles, liquid oxygen that can be put in high pressure gas cylinders for medical or welding cutters like an oxygen propane cutter storage like the little jewelry scale unit I use with a 150 cu-ft O2 tank & 4.5 gal propane tank, it makes tiny little brazing cutting white hot flame that can color texture stainless or titanium artistically :)
Most of todays commercial aircraft are fitted with 2 or 4 giant turbo-fan engines that inhale vast amounts of atmospheric air into a giant compressor at the front of the engine connected by a shaft to the power core where fuel injected & combined with the compressed air to produce hight temperature combustion and expanding exhaust gas heat & pressure that goes through the blades in the generator array to impart mechanical engine on the shaft to drive the compressor.
The compressor in the turbofan compresses & thereby heats the incoming air, then in the combustion section adds fuel in annulus burner modules optimized with CFD CAD FEA engineering on computers to the hot compressed air to make a tremendous amounts of expanding hot gas to drive the exhaust turbine made with the specialized air cooled high nickel super alloys. The large ducted intake fan at the front of the engine much larger than the power core turbine, and the relative size of the power core turbo to the large fan is called the bypass ratio, greater than 10:1 in recent engines. As turbofan engines improved, the diameter of the front intake fan increased, thereby increasing the bypass ratio. Aluminum titanium alloy blades, composite polymer blades that actually flex into shape as the engine spins up, actively controlled blades & ceramic blades made of zirconia or similar super advance ceramics are all technologies to make tough bird strike impact resistant fan blades for high bypass passenger aircraft engines for the A320 from Airbus or latest Boeing 373 variant, for example. Improve the bypass ratio has several beneficial effects, by radically helping to cool the engines hot sections, lubricating oils, bearings & blades, while also keeping the fuel & other metals in the hot combustion & exhaust section at lower temperatures that enhance their useful operating life.
From wikipedia https://en.wikipedia.org/wiki/Turbofan
I mentioned ceramics earlier because advance ceramics are poised to radically improve aircraft engines, by enabling much higher combustion temperatures & correspondingly improved thermal efficiency. The surface texture of ceramic blades can be coated in a catalytic slurry to radically reduce oxide of nitrogen emissions, HC emission & otherwise clean up the turbo-fan exhaust making air quality improve near & around airports where these improved engines displace older dirtier models.
Electric motors have improved so much that hybrid aircraft turbofan engines are being developed that enable e-boost on takeoff & energy recover when the landing sequence engaged. There are some highly novel combustion techniques from scramjets & ramjets & energy recovery techniques that can further improve fuel economy, reduce fuel consumption, improve range, top speed & overall performance a lot more. The surfaces in the engine, the blades for example, can greatly benefit from precise texturing. Turns out that turbulence can be reduced on a textured surface better than a diamond powder honed smooth surface. Texturing can also help to reduce the temperature of the exhaust turbine blades, greatly improving their functional life.
Today people make ~1.5 billion aircraft journeys per year! Eventually in the 1980 in America, Frank Whittle was recognized for his prime pioneering work on jet propulsion, turbo-jets & turbofans, the base propulsion technology energizing nearly air aircraft today. The turbo aero-engine was novel because it could burn many different fuels of many different grades & was truly flex-fuel or poly-fuel by nature. Kerosine, Diesel & Jet A are very similar chemically as fuels for example.
In the UK the descendent industrial aircraft propulsion technology leadership also its only remaining commercial player, Rolls Royce Jet Engines :) The Concorde supersonic passenger aircraft enabled Frank Whittle to cross the Atlantic from the UK to America in only 3.5 hours ^^ sadly that project was scrapped because of poor fuel economy as fuel prices continued to rise in the early 2000's.
The Concorde was also a complicated mess to build & maintain & the aging fleet become less feasible to operate commercially. Delays and cost overruns increased the program cost to £1.5–2.1 billion in 1976, (£9.44 billion–13.2 billion in 2021)
Able to reach a speed of 1354 mph, it was a trail blazer! Supersonic flight more than halved travel times, but sonic booms over the ground limited it to transoceanic flights only. The Concorde Airliner could maintain a supercruise up to Mach 2.04 (2,167 km/h; 1,170 kn; 1,347 mph) at an altitude of 60,000 ft (18.3 km).
25 July 2000, Air France Flight 4590 crashed shortly after take-off with all 109 occupants and four on ground killed; the only fatal incident involving Concorde. Commercial service was suspended until November 2001, and Concorde aircraft were retired in 2003 after 27 years of commercial operations. Most Concorde aircraft are on display in Europe and America today :)
From Wikipedia / https://en.wikipedia.org/wiki/Concorde
Concorde pioneered the following technologies:
For high speed and optimisation of flight:
- Double delta (ogee/ogival) shaped wings
- Variable engine air intake ramp system controlled by digital computers
- Supercruise capability
- Thrust-by-wire engines, precursor of today's FADEC-controlled engines
- Droop nose for better landing visibility
For weight-saving and enhanced performance:
- Mach 2.02 (~2,154 km/h or 1,338 mph) cruising speed for optimum fuel consumption (supersonic drag minimum and turbojet engines are more efficient at higher speed) Fuel consumption at Mach 2 (2,120 km/h; 1,320 mph) and at altitude of 60,000 feet (18,000 m) was 4,800 US gallons per hour (18,000 L/h).
- Mainly aluminum construction using a high temperature alloy similar to that developed for aero-engine pistons.This material gave low weight and allowed conventional manufacture (higher speeds would have ruled out aluminum)
- Full-regime autopilot and auto-throttle allowing "hands off" control of the aircraft from climb out to landing
- Fully electrically controlled analogue fly-by-wire flight controls systems
- High-pressure hydraulic system using 28 MPa (4,100 psi) for lighter hydraulic components, tripled independent systems ("Blue", "Green", and "Yellow") for redundancy, with an emergency ram air turbine (RAT) stored in the port-inner elevon jack fairing supplying "Green" and "Yellow" as backup.
- Complex air data computer (ADC) for the automated monitoring and transmission of aerodynamic measurements (total pressure, static pressure, angle of attack, side-slip).
- Fully electrically controlled analog brake-by-wire system
- Pitch trim by shifting fuel fore-and-aft for center-of-gravity (CoG) control at the approach to Mach 1 and above with no drag penalty. Pitch trimming by fuel transfer had been used since 1958 on the B-58 supersonic bomber.
- Parts made using "sculpture milling", reducing the part count while saving weight and adding strength.
- No auxiliary power unit, as Concorde would only visit large airports where ground air start carts are available.
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