Simulation of supercritical flows in rocket-motor engines: application to cooling channel and injection system

Abstract

To address physical modeling of supercritical multicomponent §uid §ows, ideal-gas law must be changed to real-gas equation of state (EoS), thermodynamic and transport properties have to incorporate dense §uid corrections, and turbulence modeling has to be reconsidered compared to classical approaches. Real-gas thermodynamic is presently investigated with validation by NIST (National Institute of Standards and Technology) data. Two major issues of Liquid Rocket Engines (LRE) are also presented. The ¦rst one is the supercritical §uid §ow inside small cooling channels. In a context of LRE, a strong heat §ux coming from the combustion chamber (locally φ ≈ 80 MW/m 2 ) may lead to very steep density gradients close to the wall. These gradients have to be thermodynamically and numerically captured to properly reproduce in the simulation the mechanism of heat transfer from the wall to the §uid. This is done with a shock-capturing weighted essentially nonoscillatory (WENO) numerical discretization scheme. The second issue is a supercritical §uid injection following experimental conditions [1] in which a trans-or supercritical nitrogen is injected into warm nitrogen. The two-dimensional results show vortex structures with high §uid density detaching from the main jet and persisting in the low-speed region with low §uid density.

Large-eddy simulation of supercritical fluid injection

“…A part of the light surrounding nitrogen is then very quickly embedded into the main core jet before the jet opening. Some structures observed after one third of the domain, are detaching from the core jet and bear a similarity to those observed in 2D simulations with DNS resolution [28]. They could require here a finer mesh resolution for a very fine tracking of them as they dissolve quite quickly.…”

“…1 http://www.coria-cfd.fr/index.php/SiTCom-B. To simulate supercritical flows, SiTComb-B numerical code features real gas thermodynamic [28]: a cubic EoS replaces the classical ideal gas law, linking the pressure, p, temperature, T and density, , as…”

Large-Eddy Simulation of a Supersonic Burner

“…The supersonic burner (SSB) of Cheng et al 9 is investigated with SiTComB a (Simulation of Turbulent Combustion with Billion of points) numerical code, 12,13,14,15 which solves the unsteady compressible reacting Navier-Stokes equation system on Cartesian meshes. It was mainly designed to perform Direct Numerical Simulation (DNS) and highly resolved Large Eddy Simulation (LES) on thousands of processors.…”

LOx/CH4 mixing and combustion under supercritical conditions

“…Numerical Solver The numerical solver used for this study is called SiTCom-B (Simulation of Turbulent Combustion with Billions of points) and has already been described and used in previous studies. 13,1,14,15,16 It is a finite volume code that solves the unsteady compressible reacting Navier-Stokes equations system on cartesian meshes. This new version of SiTCom is designed to perform DNS and highly resolved LES on thousands of processors.…”

“…In SiTComb-B, 16 real gas thermodynamics follows Meng and Yang's recommendations 17 and is then based on the Soave-Redlich-Kwong (SRK) equation of state which replaces the classical perfect gas law. Pressure (p), density (⇢) and temperature (T ) are linked with the following cubic equation of state:…”