JNTU B.Tech III AEROSPACE PROPULSION- II Previous Question Paper (December - 2018 - R15)

Explain various performance parameters for High speed propulsion systems.

Explain the basic concept of Orbital injection.

Explain the significance of Supersonic combustion.

Explain the terms Spill over drag and Plume drag.

How the performance of chemical rocket engines affected with atmospheric conditions.

What is a propellant? Classify Liquid propellants.

Explain the types of combustion instabilities in rocket engines.

Explain the criterion for selection of a rocket propulsion system.

What are the limitations of a chemical rocket engines.

Explain how thrust is generated in electric propulsion system.

Derive Breguet Range equation for cruise operation.

Explain different trajectories involved in trans-atmosphere and space flight missions with neat sketches.

With a neat sketches explain simple cruise and Air superiority mission profile for a jet aircraft.

An aircraft flies at 960 kmph. One of its turbojet engine takes in 40 kg/s of air and expands the gases to the ambient pressure. The air-fuel ratio is 50 and the lower calorific value of the fuel is 43 MJ/kg. For maximum thrust power determine: i) Jet velocity ii) thrust iii) Specific thrust iv) thrust power v) propulsive, thermal and overall efficiencies.

Draw a neat sketch of supersonic diffuser for a ramjet engine with oblique and normal shocks.

Describe the working of a Ramjet engine. Depict various thermodynamic processes occurring in it on h-s diagram.

A ramjet engine has the following data: Altitude= 6.5 km, Flight Mach number= 4.0, Air fuel ratio = 50, calorific value of the fuel used is 44.18 MJ/kg. Diffuser inlet diameter = 0.5 m, γ=1.4, R= 287 kJ/kg K, for air and the products of combustion, efficiencies of the diffuser, combustor and nozzle are 0.85, 0.98 and 0.95 respectively. Determine: i) Ideal cycle efficiency ii) Flight speed iii) Air and fuel consumptions iv) Diffuser pressure ratio v) Maximum temperature in the engine vi) Nozzle pressure ratio and exit mach number vii) Thrust and air specific impulse.

Derive the following relations for aircraft engines and state the assumptions used in the derivations for the above expressions. i) Thrust in a turbojet engine ii) Specific impulse.

A rocket flies at 10,080 kmph with an effective exhaust jet velocity 1400 m/s and propellant flow rate of 5.0 kg/s. If the heat of reaction of the propellants is 6500 kJ/kg of the propellant mixture. Determine: i) Propulsive efficiency and Propulsive power ii) Engine output and thermal efficiency iii) Overall efficiency.

Explain briefly three important applications of rocket propulsion.

Determine the maximum velocity of a rocket and the altitude attained from the following data: Mass ratio = 0.15, Burnout time = 75 s, Effective jet velocity 2500 m/s What are the values of the velocity and altitude losses due to gravity? Ignore Drag and assume vertical trajectory

Write notes on the following with respect to the solid propellant rocket motor: (i) Rocket motor case (ii) Igniters.

Sketch the various configurations of solid propellants and give their salient features.

What do you understand by thrust vector control? Explain briefly the various methods to control the thrust vector of a solid rocket motor.

Explain the engine cycle for turbo pump feed liquid propellants.

Explain the Relationship between the burning rate and chamber pressure with respect to a solid propellant rocket motor.

Draw neat sketches explaining the general working of electric propulsion rocket engine

With the help of a diagram explain a typical ion propulsion system. What are the sources of losses in the system and how they are prevented?

Write a short note on solar thermal propulsion system.

Draw neat sketches explaining the general working of nuclear rocket motor.