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...

Introduction T HE propulsion system of a short takeoff and vertical landing aircraft, such as the F-35 Joint Strike Fighter, must operate over a wide range of conditions, provide good fuel efficiency at cruise, and deliver high thrust in augmented mode for transonic acceleration and supersonic operation. The propulsion system must be efficient for both high-speed flight and during hover, while ...

The generation of acoustic tones in four round jets at a Mach number 0.9 impinging on plate distance $L=6r_0$ from the nozzle exit, where $r_0$ is radius, has been investigated by large-eddy simulation. Three plates are perforated holes diameters $h=2r_0$ , $3r_0$ and $4.4r_0$ centred jet axis, whereas fourth no hole, order to study effects hole flow fields. In all cases, emerge near field, ups...

The internal heat transfer performance and flow structures of a sweeping jet film composite cooling on flat plate were numerically studied. Sweeping consists fluidic oscillator 20 cylindrical holes; the direct is formed by removing feedback from oscillator, which different traditional nozzle. Four mass rates coolant considered, inclination angle hole was 30°. Conjugate Heat Transfer method (CHT...

The attention of the present paper is focused on the intensive heat removal with arrays of impinging jets. Three jet configurations are tested which involve variation of geometric parameters such as nozzle shape, diameter and nozzle-tonozzle spacing and impingement distance and of flow rate. The convective heat transfer coefficient is measured with infrared thermography applied to the heatedthi...

in this study, an electrostatic sprayer which had been previously designed and constructed was evaluated in order to quantify the charging of droplets. liquid atomization was achieved by using an ultrasonic nozzle. the nozzle maximum flow rate was 25 milliliters per minute and vibration frequency was about 30 khz. the induction method was used for charging the output droplets. all experiments w...

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 ...