I am turning to you with a few simple questions, but a fact is, that it is not so easy to get answers. I have already sent some e-mails to turbofan engine producers, however, no response in my e-mail box.. Perhaps, I am marginal person for them. I study fluid engineering and I am trying to solve a task of fuel consumption reduction during aircraft taxiing on the ground. For my work I need to know the information about the engines ordinary used on mid-size jet aeroplanes, like CFM56-5B,CF34-8C5, IAE V2500, Rolls&Royce RB211-535, Pratt&Whitney PW1000G, PW 2000, PW6000, Ivchenko-Progress D-436-148 or similiar types. I would like to know, what time the engines need for start-up and heating for take-off regime, fuel consumption on idle running, during taxi and during flight at standard cruising level? I am interested also in fuel consumption of APU's used on theese types of aircrafts? I would be thankful for every information or another kind of help!
Greetings from a retired old pilot and air accident investigator. Am wondering if you have studied some of the available text books on gas turbine aero-engines; such as the one turned out by Rolls-Royce? Turbofans are pretty well ready for take-off shortly after start. They do not require 'warming-up' as do piston engines. Their fuel-flow at ground idle rpm is dependent on air temperature and pressure altitude and is out of the pilot's control. The fuel-flow during taxi is dependent on factors such as aircraft weight, relative wind direction, the firmness of the taxiway, taxiway gradients, tyre pressures and temperatures, taxi groundspeed etc. Most of these are not within the pilot's control. APU fuel-flow depends on the torque load being placed upon it...how much electrical demand etc. Climb and cruise power fuel-flows depend on air temperature, what percentage of power is used and what Mach number the pilot decides to use. Different airlines may have different power/speed policies to others. But the weight of the aircraft has far and away the largest effect on fuel-flow. The difference between power required at the beginning of a sector and the end is enormous. I feel you really need to get into the books to gain a basic understanding of gas-turbine engines and aerodynamics. Gradually things will clarify as you learn more. You can find out a great deal by a dedicated search using Google. Try a range of Key words and phrases such as Fuel Control Unit, FADEC, Turbojet, Pratt and Whitney, Rolls-Royce, Thermodynamics, Entropy, Fluid Dynamics, Jet Engines, Aerodynamics, Range Flying etc etc. Let us know how you get on.