Sharif Digital Repository

Thrust termination dynamics of a solid propellant rocket motor that is crucial to the performance of the rocket has been analyzed. Active thrust termination or reversing of a separating motor facilitate the staging process and enhance the performance of a multistage rocket. This can be achieved by opening a secondary nozzle located on the motor head and causing rapid depressurization of the motor chamber. The strong dependence of the solid propellant burning rate on the chamber pressure causes a transient nonlinear behavior that can result in premature dynamic extinguishments of the motor. It was confirmed that there is a maximum achievable level of equilibrium reverse thrust due to... 

This paper presents the application of a relatively new technique of fluidic thrust-vectoring (FTV), named Co-flow, for a small gas-turbines. The performance is obtained via experiment and computational fluid dynamics (CFD). The effects of a few selected parameters including the engine throttle setting, the secondary air mass-flow rate and the secondary slot height upon thrust-vectoring performance are provided. Thrust vectoring performance is characterised by the ability of the system to deflect the engine thrust with respect to the delivered secondary air mass-flow rate. The experimental study was conducted under static conditions in an outdoor environment at Cranfield University workshop... 

This paper aims to investigate aeroelastic stability boundary of subsonic wings under the effect of thrust of two engines. The wing structure is modeled as a tapered composite box-beam. Moreover, an indicial function based model is used to calculate the unsteady lift and moment distribution along the wing span in subsonic compressible flow. The two jet engines mounted on the wing are modeled as concentrated masses and the effect of thrust of each engine is applied as a follower force. Using Hamilton's principle along with Galerkin's method, the governing equations of motion are derived, then the obtained equations are solved in frequency domain using the K-method and the aeroelastic...