Question

1. VTOL Engine Forces A propulsion system for a newP VTOL (vertical takeoff and landing) aircraft is being tested. i The design is a basic turbojet AP with the geometry shown in the P figure to the right. The engine is mounted on a pod in a test cell that keeps the engine stationary by exerting the necessary reaction forces to balance the forces generated by the engine. Gas turbine Pe PeTe The test cell provides air to the engine with a mass flux /A at density ρι and pressure pl Because of external acceleration or deceleration prior to the inlet, P is not necessarily equal to the ambient pressure pa. The engine redirects the flow downwards such that it leaves in the vertical direction at a speed ue, pressure Pe, and temperature Te. The exhaust pressure Pe is, in general, also not equal to Pa Inlet Assume the mass of fuel added to the flow and viscosity are negligible. (a) First consider just the inlet portion of the engine. The flow leaves the inlet at u2 and p2 through an area A2. Derive the equation for the necessary horizontal reaction force (if any) arising b)Now consider the entire engine. Derive the equation for the necessary reaction force (if any) (c) Again considering the entire engine, derive the equation for the necessary reaction force (if (d) In the case where Pi Pe Pa, comment on the direction the engine would move in the (e) Solve the equations from (b) and (c) for the case of p-pe -Pa, mi/A - 40 kg/m's, p- from the flow moving through the inlet. to prevent the engine from moving horizontally any) to prevent the engine from moving vertically absence of the pod. Le would it move left/right and/or up down and why? 1.2 kgm', ue 250 m/s, and Te = 600 K.

Answer 1