Numerical Modeling of High-Pressure Cryogenic Sprays

Abstract

Super-critical mixing and combustion phenomena involves a large spectrum of interconnected physical processes which determine complexity in the problem formulation. Near critical or trans-critical condition the reacting mixture exhibits large variation in thermodynamic and transport properties, which affect drastically the mixing and combustion processes. The aim of this investigation is the implementation by user defined routines of thermodynamically consistent real gas mixing equation of state into the commercially available CFD-code ANSYS Fluent and the validation using experimental data. CFD simulations have been also performed by using different approaches: the Soave Redlich-Kwong real gas model and Peng Robinson have been implemented to model the physical properties of the species. This work is divided in two parts: in the first part a numerical analysis has been conducted to study the nitrogen high pressure flow in liquid rocket near the critical point , in the second the numerical study of the LOX/H2 and LOX/CH4 injection, mixing and combustion in liquid rocket engines with shear coaxial injectors, at supercritical conditions by using one-step reaction mechanism and detailed chemical kinetic reaction mechanism. Nomenclature p pressure R gas constant T temperature V specific volume v molar volume ω acentric factor H enthalpy Cp isobaric specific heat Z compressibility factor Cv isochoric heat capacity S entropy � dynamic viscosity Mw molecular weight k thermal conductivity Yi mass fraction of species i Superscripts