What type of engine oil is used in aviation?
Type II oils are ester-based synthetics, used today by virtually all turbine powered aircraft worldwide, and have proven to be the most technically and commercially successful and long-lived oils developed for aviation.
What kind of oil do gas turbine engines use?
When early gas turbine engines came into use in the 1940's, mineral oils were used as lubrication. These mineral oils quickly reached the limits of their capability, which lead to extensive research in the late '40s and early '50s.
What is a turbojet engine?
The turbojet is an airbreathing jet engine, typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, and a turbine (that drives the compressor).
What additives are used in jet engine oil?
The additives used are typically antioxidants, metal passivators, antifoamants, anti-wear and possibly load carrying or corrosion inhibitor additives. All jet oil additives are "ashless" containing no metallic components eliminating the formation of metallic soaps (metal containing sludges) formed from the oil alone.
What kind of oil do jet engines use?
Mobil Jet Oil 254 is recommended for aircraft gas turbine engines of the turbo-jet, turbo-fan, turbo-prop, and turbo-shaft (helicopter) types used in commercial and military service.
Is synthetic oil used in turbine engines?
Almost all turbine engine oils are fully synthetic. There are a few really old engines and some ex-Soviet bloc aircraft that operated on mineral-based turbine oils, but almost all of the modern U.S.-built jet and turboprop engines operate exclusively on synthetic oils.
What is the difference between turbine oil and hydraulic oil?
Hydraulic oils require higher anti-wear, anti-foam, and anti-emulsification features. On the other hand, turbine oils have a higher demand for anti-rust, anti-corrosion, and anti-foaming properties.
Is 5W 30 thicker than 10W 30?
So both the oils 5W–30 and 10W–30 have exactly the same viscosity (SAE 30) when your engine is running, and will perform in the same way. However, the 10W–30 oil will be thicker (higher viscosity) than the 5W–30 when it is cool.
What is turbine oil made of?
Turbine oil formulations are relatively simple; they are a mixture of the following ingredients: Base oil, corrosion inhibitors, oxidation inhibitors, defoamants, and demulsifiers. The base oil is usually 97 percent or more of the turbine oil formula.
What is turbine engine oil?
Turbine engine oils are used to lubricate aircraft turbine engines and jet engines to ensure excellent performance and to help them last longer.
What are some characteristics of turbine engine oil?
7 properties of turbine oilsAppropriate viscosity. ... High water separation capacity. ... Non corrosive and prevents rust formation. ... Stability against oxidation. ... Resistance to foaming. ... High air separation capacity. ... Stability in long-term storage.
What is turbine oil used for?
Phillips 66® Turbine Oil is a very high-quality, rust and oxidation (R&O)-inhibited circulating oil developed for use in industrial steam turbines, rotary air compressors, and many other industrial applications. It is specially formulated to protect against sludge and varnish formation to provide long service life.
How does airflow work on reciprocating engines?
Airflow around the cooling fins transfers heat from the cylinder head to the air.
What is dispersant in oil?
The dispersant causes sludge-forming materials to repel each other and remain in suspension until they can be trapped by the oil filter or drained. This keeps the oil passages and ring grooves free of harmful deposits, and the inside of the engine clean.
What is the purpose of cowling?
The cowling performs two main functions: it streamlines the engine area to reduce drag, and is used together with the baffles and cowl air seals to direct airflow over the cylinders for cooling.
What is a cowling control?
They are used to control the amount of airflow through the cowling. They are either mechanically, electrically, or hydraulically operated.
What does it mean when a car has a metal particle?
Depending on the type and size of the metal particles, this usually indicates abnormal wear and possible engine internal failures.
What is friction reduction?
To reduce friction between moving parts and remove heat.
Why are turboprops noisy?
In essence, it’s largely because a turboprop is usually more suited to lower air speeds which is often important where runways limited in length as they can land and take off in a shorter distance. Turbofans are faster and more efficient at high speed as well as being a good deal quieter. So turboprops are generally suited to shorter runs and smaller airports than turbofans whilst turbofans are better for longer distances but require longer runways. That said, there are routes where you will find both as the fuel efficiency and lower maintenance costs of the turboprop might outbalance the benefits of the turbofan in speed.
What is Mobil Jet Oil 387?
Mobil Jet™ Oil 387 is Exxon-Mobil’s latest. Proactively developed to respond to the evolving needs of customers and the industry, Mobil Jet Oil 387 is their most advanced turbine oil ever developed.
What type of starter do jet engines use?
Rather interesting question. It’s not like your car engine, but it does begin with a starter (which can be driven by either compressed air or electricity - depends on the type of aircraft). Generally, the smaller jets and turboprops use electric starters to begin the shaft rotation. The transport category aircraft mostly use air turbine starters which use compressed air.
Why do turbine engines need oil?
Due to how turbine engines operate, the oil is in a much kinder environment than piston engine oil. No piston blow by, so no corrosive gases. Oil temperature is lower, so less thermal stress. Lubricates mostly bearings, so no scraping or shear forces like a cylinder wall. All this means the oil stays very clean and lasts a very long time. I can't say how often a turbine engine needs an oil change because I don't know. They're such a long interval that I've simply never encountered an oil change.
What is the best jet oil for a jet engine?
Mobil Jet Oil 254 is recommended for aircraft gas turbine engines of the turbo-jet, turbo-fan, turbo-prop, and turbo-shaft (helicopter) types used in commercial and military service. It is also suitable for aircraft-type gas turbine engines used in industrial or marine applications. It is also compatible with other synthetic gas turbine lubricants meeting MIL-PRF-23699. However, mixing with other products is not recommended because the blend would result in some loss of the superior performance characteristics of Mobil Jet Oil 254.
What type of jet engine is used in the GE CF6-80?
Our fleet of PW4000 engines and GE CF6–80 engines used a variety known as Mobil Jet Type II (MIL-PRF-23699G).
How much does a jet engine cost?
Because a new large commercial jet engine today costs about $24 million dollars. Multiply that by 2 for an aircraft. But really, the manufacturer first puts out an engine, and I am talking decades ago with flaws, but operable. Engines are continually under improvement. Safety has to be No 1. Pretesting and following engines in service keeps them on their toes. If I found a defect in an engine that I had never seen before, I could ask GE and they would probably have every detail on this defect already including the probability of failure or not. As an airline, you don’t just buy an engine, you buy experience with warranties. Often major airlines have a Engine Representative at their facility all the time.
How many oil sumps are needed for an engine?
The oil sumps within an engine oil system require a minimum of two oil sumps distributed along the main shaft line, and sometimes more than four. To ensure the oil is retained within the oil circuit, each oil sump is pressurised and sealed. However, it is vital that the pressure inside the oil sump remains lower than the pressure outside the sump.
Why is jet oil important?
A jet engine oil system is vital to any plane as it is responsible for providing a continuous flow of oil to the engine of the aircraft. The recirculatory system is needed to store, cool, carry, and distribute oil necessary for lubricating and cooling every gear, spline, bearing and carbon seal.
What happens if you put too much oil in a bearing?
If the level of lubricant is either too high or too low, excessive heat can be generated, in turn accelerating the degradation of the oil and shortening the life of the bearing. If the oil level is too high, a condition often referred to as ‘churning’ can occur. In this situation, air is whipped into the oil, which along with the induced heat raises the oxidation rate, shortening the effective life of the oil. Too little oil means there is not sufficient contact to lubricate the bearing and act as a heat sink to carry away the normal levels of heat generated by the bearing.
What is engine oil system?
The engine oil system contains a monitoring capability that provides information to the cockpit engine health by measuring oil parameters such as oil supply pressure and temperature. In more advanced on-board computerised systems, additional factors are recorded and analysed either in real time or after landing. These can include scavenge temperatures, oil quantity in the tank and quantity of debris released by the sumps.
What is an antisiphon system?
The implementation of an antisiphon system prevents tank draining due to the siphoning effect created upon engine shutdown through the supply network when the tank is located above a supply nozzle. A pressure relief valve protecting the supply pump prevents abnormal output pressure during cold starts.
What is a JT3C?
The J57/JT3C was developed into the J52 turbojet, the J75/JT4A turbojet, the JT3D/TF33 turbofan, and the XT57 turboprop (of which only one was built). The J57 and JT3C saw extensive use on fighter jets, jetliners, and bombers for many decades.
What is the J57 engine?
(June 2020) The J57 was a development of the Pratt & Whitney XT45 (PT4) turboprop engine that was originally intended for the Boeing XB-52. As the B-52 power requirements grew, the design evolved into a turbojet, the JT3. Pratt & Whitney designed the J57 to have a relatively high overall pressure ratio ...
What is the titanium in a J57?
Many J57 models shipped since 1954 contained 7-15% of Titanium, by dry weight. Commercially Pure Titanium was used in the inlet case and low pressure compressor case, whereas the low pressure rotor assembly was made up of 6Al-4V Titanium alloy blades, discs and disc spacers.
How many spools does a P&W turbofan have?
Within a few months both P&W and Bristol had had a first run of their prototypes. Both demonstrated superb handling. Today most civil and military turbofans have a two spool configuration, a notable exception being the Rolls-Royce Trent turbofan series which has three spools.
What is a low pressure compressor?
In a two-spool arrangement the first compressor, usually called Low Pressure Compressor (LPC), is driven by the Low Pressure Turbine (LPT), and supercharges another unit known as the High Pressure Compressor (HPC) itself driven by the High Pressure Turbine (HPT).
Where is the J57 cutaway?
A J57 cutaway is on display at the New England Air Museum, Bradley International Airport, Windsor Locks, CT. A J57 cutaway is on public display at the Aerospace Museum of California. It is s/n 35 used on the XB-52 program.
What engine did Boeing use for the 707?
Production figures were in the thousands, which led to a very reliable engine. Consequently it was only natural for Boeing to choose the J57 civil variant, the JT3C, for their 707 jetliner. Douglas did likewise with their DC8.
How does a turbojet engine work?
Schematic diagram showing the operation of a centrifugal flow turbojet engine. The compressor is driven by the turbine stage and throws the air outwards, requiring it to be redirected parallel to the axis of thrust.
How did turbojet engines affect commercial aviation?
Turbojet engines had a significant impact on commercial aviation. Aside from giving faster flight speeds turbojets had greater reliability than piston engines, with some models demonstrating dispatch reliability rating in excess of 99.9%. Pre-jet commercial aircraft were designed with as many as four engines in part because of concerns over in-flight failures. Overseas flight paths were plotted to keep planes within an hour of a landing field, lengthening flights. The increase in reliability that came with the turbojet enabled three- and two-engine designs, and more direct long-distance flights.
What was the first British aircraft to fly with a turbojet engine?
The Whittle W.2 /700 engine flew in the Gloster E.28/39, the first British aircraft to fly with a turbojet engine, and the Gloster Meteor. In 1928, British RAF College Cranwell cadet Frank Whittle formally submitted his ideas for a turbojet to his superiors. In October 1929 he developed his ideas further.
Why are turboprops better than turbojets?
Turbojets have been replaced in slower aircraft by turboprops because they have better specific fuel consumption. At medium to high speeds, where the propeller is no longer efficient, turboprops have been replaced by turbofans. At these transonic speeds, the turbofan is quieter and has better range-specific fuel consumption than the turbojet. Turbojets can be highly efficient for supersonic aircraft.
What year did the J85-GE-17A turbojet engine come out?
J85-GE-17A turbojet engine from General Electric (1970) General Electric in the United States was in a good position to enter the jet engine business due to its experience with the high-temperature materials used in their turbosuperchargers during World War II.
Why do turbojet engines have intakes?
These vanes also helped to direct the air onto the blades. The air flowing into a turbojet engine is always subsonic, regardless of the speed of the aircraft itself.
How does a combustor work?
The burning process in the combustor is significantly different from that in a piston engine. In a piston engine, the burning gases are confined to a small volume, and as the fuel burns, the pressure increases. In a turbojet, the air and fuel mixture burn in the combustor and pass through to the turbine in a continuous flowing process with no pressure build-up. Instead, a small pressure loss occurs in the combustor.