Ejectors are known to be beneficial to vapor compression cycle performance as they can recover the kinetic energy released during the expansion instead of dissipating it in a throttling process. It is desirable to introduce an adjustable feature to the ejector so that ejector cycle performance can be optimized under different working conditions, which could make ejector technology more suitable...

The present paper reports the results of an experimental investigation influence coolant to mainstream density ratio (DR) on thermal and aerodynamic behavior a nozzle vane cascade with platform cooling through slot or discrete holes. Measurements were carried out 6 at low (1.6%) high (9%) inlet turbulence intensity level, blowing ratios (BR) varied in range 1-2. Tests performed injecting carbon...

This study conducts an experimental study concerning the improvement of nozzle/diffuser micropump design using some novel no-moving-part valves. A total of three micropumps, including two enhancement structures having two-fin or obstacle structure and one conventional micro nozzle/diffuser design, are made and tested in this study. It is found that dramatic increase of the pressure drops across...

We present a three-dimensional Reynolds-averaged Navier–Stokes investigation of the impact on nozzle aerodynamic performance of deflector vanes used for noise suppression in separate-flow turbofan engines. The vanes are installed in the bypass duct and deflect the bypass plume downward relative to the core plume. This study considers a single pair of vanes, with a NACA 0012 airfoil section, ins...

The present work describes a numerical methodology and its experimental validation of the flow development inside outside orifices during pilot injection, dwelt time subsequent start injection cycle. compressible Navier-Stokes equations are numerically solved in six-hole injector imposing realistic conditions needle valve movement considering addition time-dependent eccentric motion. motion is ...

The fracture and crack growth of mechanical structures is a usual phenomenon which is due to the application of tensile, cyclic loading or thermal stresses on the structure. So introducing of methods to prevent the crack growth is useful. Afterward, one of the repairing methods of crack growth, consisting to make a hole in the crack tip to elimi-nate the sharp corners, was explained. This metho...

We establish the existence and stability of multidimensional transonic flows with transonic shocks through an infinite nozzle of arbitrary cross-sections, including a slowly varying de Lavel nozzle. The transonic flow is governed by the inviscid steady potential flow equation with supersonic upstream flow at the entrance, uniform subsonic downstream flow at the infinite exit, and the slip bound...