Large-Eddy Simulations of a Supersonic Heated Jet

Abstract

Large-eddy simulations of imperfectly expanded jet flows from a convergent-divergent nozzle with a heated (600K) and a cold jet conditions have been carried out. Mach wave radiation is present outside the jet core and the heated jet shows a much larger density shear-layer spreading than the cold jet. The potential core length is shortened, but the shock-cell shape and shock-cell spacing remain similar to those shown in the cold jet. It is found that the Crocco-Busemann equation captures well the correlation between the temperature and the axial velocity in the cold jet, but it underestimates the nonlinear variations in the shock-containing region in the heated jet. Temperature effect has more impact on the high-frequency components of pressure fluctuations near the nozzle exit, but the impact moves to low-and mid-frequency ranges further downstream. The convection speed of the near-field pressure waves increases with the temperature. The addition of inflow random pressure perturbations increases the velocity shear-layer spreading and turbulence intensities near the nozzle exit, but it reduces the screech intensity and the peak intensity of the overall pressure fluctuation level. The heated jet is found to be more sensitive to the inflow pressure perturbations than the cold jet.

Efficient Supersonic Jet Noise Simulations Using JENRE

“…The flow structure and acoustics of these conic convergent-divergent nozzles have been presented elsewhere [13] in detail and will not be repeated here. In more recent work, our simulations have been extended to include the effects of inflow turbulence [14] and jet heating [10], since realistic operating conditions involve hot turbulent, exhaust jets. The results from the simulations of heated jets are in agreement with observations made in the literature.…”

“…An AIAA journal paper addressing verification and validation of supersonic jet exhaust flows has been published [3]. Previous studies have looked at the effect of exhaust temperatures on flow instabilities [2,10], the impact of some flow modifiers on engine performance and noise from supersonic rectangular jets [1] and the effectiveness of various noise reduction techniques [18,19,22].…”

Simulation and Experimental Analysis of the Temperature Field of Jet Flow of Aircraft Based on CFD Theory

“…Song et al [19] have established a simulation model of jet flow of a carrier-borne aircraft, studied the influence of high temperature, high speed and high pressure jet flows on the guide plate under different deflection angles, and compared the simulation results with the experimental results. Liu et al [20], [21] have studied the impact of a typical aircraft carrier deck and jet blast deflector (JBD) under the condition of under-expansion air flow with finite element method. Sun et al [22] have analyzed the influence of jet flow of a carrier on the wind field, velocity field and pressure field on the deck based on the theory of computational fluid dynamics.…”

Development of high order WENO schemes for large-eddy simulation of compressible flows in OpenFOAM

“…Liu, et al [130] have observed that, although inflow forcing causes the turbulence levels to rise faster close to nozzle exit, its impact is much smaller further downstream. They also noted a reduction in screech amplitude due to inflow forcing.…”