Numerical study for the influences of nozzle exit position, mixing, and diffuser section lengths on performance of CRMC ejector

The purpose of the study was to carry out a numerical simulation of the interaction of an underexpanded supersonic jet flowing into a flooded space with a normally located obstacle, and with the underlying surface. We performed the calculations in the ANSYS Fluent software package and presented flow patterns. For the case when the obstacle is located normally to the axis of the jet, we compared the pressure distribution in the radial direction with experimental data and made a conclusion about the changes in the integral load on the wall with a change in the distance to the nozzle exit. For the case when the obstacle is parallel to the jet axis, we presented the pressure distribution along the wall in the plane of symmetry, estimated the relative net force acting on the underlying surface, analyzed the nature of its change at various values of the off-design coefficient, the Mach number on the nozzle exit and the distance to the jet axis.

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Numerical study of nozzle exit condition effects on jet development

AIAA Journal ◽

10.2514/3.13923 ◽

1998 ◽

Vol 36 ◽

pp. 986-993

Author(s):

Thomas S. Chyczewski ◽

Lyle N. Long ◽

Philip J. Morris

Keyword(s):

Nozzle Exit ◽

Numerical Study

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Numerical Study of the Inlet Conditions Influence on Laminar Plane Wall Jets

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.273-276.406 ◽

2008 ◽

Vol 273-276 ◽

pp. 406-412

Author(s):

Amèni Mokni ◽

Jamel Kechiche ◽

Hatem Mhiri ◽

Georges Le Palec ◽

Philippe Bournot

Keyword(s):

Nozzle Exit ◽

Numerical Stability ◽

Numerical Study ◽

Thermal Characteristics ◽

Core Region ◽

Uniform Grid ◽

Wall Jets ◽

Parabolic Profile ◽

Isothermal Plane ◽

Inlet Conditions

In this paper, we present a numerical investigation of a laminar isothermal plane two dimensional wall jets. Special attention has been paid to the effect of the inlet conditions at the nozzle exit on the flow thermal characteristics in forced convection regime. Two velocities profiles at the nozzle exit are used: uniform profile and parabolic profile. The system of equations governing the studied configuration is solved with a finite difference scheme and an implicit scheme, for numerical stability we use a staggered non uniform grid. The obtained results show, first, that the inlet conditions affect the flow in the immediate neighbourhood of the nozzle (core region) in which the flow is governed mainly by the inertias forces. At the established region the results become independent of the flow inlet conditions.

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Numerical Study of Nozzle Exit Condition Effects on Jet Development

AIAA Journal ◽

10.2514/2.469 ◽

1998 ◽

Vol 36 (6) ◽

pp. 986-993 ◽

Cited By ~ 8

Author(s):

Thomas S. Chyczewski ◽

Lyle N. Long ◽

Philip J. Morris

Keyword(s):

Nozzle Exit ◽

Numerical Study

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Numerical Study of Flow and Heat Transfer for Circular Jet Impingement on the Bottom of a Cylindrical Cavity

Journal of Electronic Packaging ◽

10.1115/1.2909331 ◽

1993 ◽

Vol 115 (3) ◽

pp. 292-297 ◽

Cited By ~ 1

Author(s):

S. Gavali ◽

K. Karki ◽

S. Patankar ◽

K. Miura

Keyword(s):

Heat Transfer ◽

Nozzle Exit ◽

Numerical Study ◽

Jet Impingement ◽

Local Heat Transfer ◽

Local Heat ◽

Separation Distance ◽

Laminar Jet ◽

Flow And Heat Transfer ◽

Impingement Surface

A numerical study is presented for an axisymmetric laminar jet impingement on a confined disk, with the spent fluid being collected through an annual channel that is concentric with the nozzle. In this study, parametric variations were made of the dimensionless separation distance between the nozzle exit and the impingement surface, of the ratio of the diameter of the impingement surface to the nozzle diameter, and of the Reynolds number. The flow field is characterized by two recirculation zones, one adjacent to the nozzle exit and the other near the confining wall. The local heat transfer distribution on the impingement surface exhibits an off-axis maximum and a local minimum near the confining wall. The nozzle separation distance has an effect on surface heat transfer only for configurations with closet confinement. The thermal boundary condition on the impingement surface is found to have little effect on the total heat transfer.

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Introductory Numerical Study on Supersonic Ejector Working with R32

EPJ Web of Conferences ◽

10.1051/epjconf/201921302096 ◽

2019 ◽

Vol 213 ◽

pp. 02096

Author(s):

Lukas Vojta ◽

Jan Kracik ◽

Vaclav Dvorak

Keyword(s):

Numerical Analysis ◽

Nozzle Exit ◽

Numerical Study ◽

Back Pressure ◽

Working Fluid ◽

Future Research ◽

Fixed Boundary ◽

Supersonic Ejector ◽

Mixing Chamber ◽

Increasing Demand

Nowadays, there is an increasing demand for devices which work efficiently with the smallest possible consumption of energy. In this regard, incorporating ejectors seems to be an interesting choice. This paper describes the numerical analysis of the flow in a supersonic ejector working with R32 (difluoromethane) as the working fluid. The ejector geometry under investigation in this paper has already been experimentally analysed, however, air was used as the working fluid. Therefore, this paper deals with a numerical analysis of the same geometry but with a different working fluid. Furthermore, the design of the ejector enabled the adjustment of a particular distance of the motive nozzle from the beginning of the mixing chamber, i.e. the nozzle exit position (NXP). This work examines the ejector numerically for eleven values of back-pressure with the NXP of two millimetres; consequently, the performance line of the ejector with fixed boundary conditions at both inlets was obtained. Finally, the obtained results are discussed and some recommendations for future research have been made.

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