in this research, the steady-state flow filed around a 3d body and rotor configuration of the robin helicopter is simulated. the rotor is modeled by an actuator disk. for this purpose, an annular computational domain replaces the rotor and some modeled source terms are added to the momentum equations. this modeling of rotor considerably speed up computational time. the flow field over this heli...

The ability of certain animal groups to fly by themselves has always stirred our imaginations. Even in the 15th century Leonardo da Vinci was famously inspired to try to build bird-like ornithopters. However, it was not until the 19th century that the nature of aerodynamic lift was understood, and it is a little more than 100 years since it was successfully applied to achieve flight by an aircr...

In this study, an unsteady aerodynamic simulation is performed to realize the influences of platform surge motion on the aerodynamic performance of a high capacity offshore floating wind turbine. A dynamic model with pitch angle control system is utilized to propose a more realistic model of wind turbine and also achieve the rated condition of the rotor. The transient effect of platform surge m...

New flight test maneuvers and analysis techniques for evaluating the dynamic response of in-flight thrust models during throttle transients have been developed and validated. The approach is based on the aircraft and engine performance relationship between thrust and drag. Two flight test maneuvers, a throttle step and a throttle frequency sweep, were developed and used in the study. Graphical ...

We compute power corrections to mean values of hadronic event shapes — the thrust and the C parameter — of tagged b quark events in electron positron annihilation, using the dispersive approach. We find that the leading power corrections are of the same type of 1/Q corrections as for event shapes in the massless case, with the same non-perturbative coefficient times a perturbatively calculable ...

In this paper, a new design of permanent magnet linear synchronous motor (PMLSM) for electromagnetic launcher system (EMLs) has been investigated in terms of the requisite amount of average launching thrust force and thrust force ripple minimization through finite element method. EMLs are a kind of technology used to develop thrust force and launch heavy loads with different applications includ...

-Presently studied is the problem of maximizing the altitude of a rocket in vertical flight in a resisting medium, when the amount of propellant is specified, known as the Goddard problem. The case is studied in which the drag coefficient is a function of the Mach number, witnessing a sharp increase in the transonic region. Analysis shows the possibility of a more complex switching structure th...

In this study an attempt has been made to study the hydrodynamic performance of pumpjet propulsor. Numerical investigation based on the Reynolds Averaged NavierStokes (RANS) computational fluid dynamics (CFD) method using structured grid, SST kω turbulence model has been carried out. The grid independence inspection is applied to verify accuracy of numerical simulation. The numerical prediction...