Problem 1: Rocket Trajectory• Write a computer code to predict flight of the V-2 rocket.

– Rocket info: http://en.wikipedia.org/wiki/V-2_rocket

– Drag (and lift) profile, next slide

– Constant thrust, constant exhaust speed

• Comment on all results

• Assumptions

– 1 DOF vertical (no lift)

– Constant gravity (then make gravity a function of altitude)

– Use the standard atmosphere under standard day conditions

– List all other assumptions you make (CG, CP, Iij, etc.)

• Extra credit

– Add a thrust profile (throttle) and variable exit velocity

– 2 DOF flight (launch angles of 90, 80, 70 and 45 degrees)

– Zero angle of attack (zero lift)

– Then include angle of attack as calculated as the angle between the rocket centerline (long axis) and the velocity vector

– Add a wind profile

– Multi-DOF simulation (gets complicated!)

– Integrate your code with predictions from NASA CEA (we will see this in 2 weeks)

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Variation of lift and drag coefficient with Mach number of V-2 rocket missile based on body cross-sectional area with jet off

2

Brayton Cycle• Identify a modern commercial or military jet engine (turbofan or turbojet)

• Plot the Brayton cycle

– P-v diagram

– T-s (or h-s) diagram

• Identify relevant parameters

• Comment on all results

• Assumptions

– Isentropic compression and expansion

– Constant gas properties and specific heats

– Non-constant gas properties (look these up in NIST or calculate on your own)

– Mix of air and kerosene (or any other jet fuel you like, such as JET-A or even RP-1)

– Show cycle for compressor and turbine efficiencies of 100, 90 and 80%

3

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BRAYTON CYCLE FOR SIMPLE GAS TURBINE

Pressure ratio 40, inlet temperature =288K, turbine temperature 1700K, turbine and compressor adiabatic efficiencies both 0.9 [Cumpsty]