An experimental and computational study showed that a passive boundary layer control device in the form of a step incorporated just downstream of a nozzle throat can be used to provide good thrust recovery. The nozzle without the step produced an overexpansion of the supersonic °ow. The computational study was performed for a full-scale nozzle under actual engine exhaust and ambient atmospheric...

The comparisons of two typical fluidic thrust vectoring exhaust nozzles including two-dimensional(2-D) nozzle and axisymmetric nozzle on aerodynamic characteristics was presented by numerical simulation. The results show: the thrust vector angles increased with the increasing secondary flow but decreased with the nozzle pressure ratio (NPR) increasing. With the same secondary flow and NPR, the ...

This paper presents the analysis of a two phase flow ejector for the transcritical CO2 cycle. A detailed simulation model of a two phase flow ejector was developed. A controllable ejector expansion device was designed, constructed, and installed in a transcritical CO2 experimental air conditioning system. System-level experimental results were obtained at different operation conditions and vari...

In gasoline engines, including conventional direct injection (GDI) engines and newly developed compression ignition (GCI) flash boiling of the spray occurs during throttling or low load operations. Superheated fuel that is injected into cylinder, where gas pressure lower than fuel’s saturation vapor pressure, experiences a fast phase change. Plume interaction collapse can occur as consequence b...

Research on the use of high pressure water jet systems to date has mainly concentrated on laboratory simulation tests and field trials on the surface. The effects of field stress have only been simulated, therefore, by sample confinement in triaxial chambers. This paper contrasts such results with data obtained from a test site located 1000 ft below the surface in a stressed barrier pillar. Dat...

Expansion work recovery by two-phase ejector is known to be beneficial to vapor compression cycle performance. However, one of the biggest challenges with ejector vapor compression cycle is that the ejector cycle performance is sensitive to working condition changes which are common in real world applications. Different working conditions require different ejector geometries to achieve maximum ...

A straightforward procedure has been developed to quickly determine an inviscid design of a hypersonic wind tunnel nozzle when the test gas is both calorically and thermally imperfect. This real gas procedure divides the nozzle into four distinct parts: subsonic, throat to conical, conical, and turning flow regions. The design process is greatly simplified by treating the imperfect gas effects ...

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...

this paper seeks to document the specific structural patterns of bit hilanis architecture which were in used in the ancient near east from the second to the first millennium b.c. the recognition of bit hilanis architectural characteristics as well as their provenances and their spread from anatoly to palestine have always remained the important issues to be addressed by art historians and archa...