Direct Numerical Simulations of LOX/H2 Temporal Mixing Layers Under Supercritical Conditions
Abstract
Direct Numerical Simulations (DNS) of a supercritical LOX/H2 temporal three-dimensional mixing layer are conducted for the purpose of exploring the features of high pressure mixing behavior. The conservation equations are formulated according to fluctuation-dissipation (FD) theory which is not only totally consistent with non-equilibrium thermodynamics, but also relates fluxes and forces from first principles. According to FD theory, complementing the low-pressure typical transport properties (viscosity, diffusivity and thermal conductivity), the thermal diffusion factor is an additional transport property which may play an increasingly important role with increasing pressure. The Peng-Robinson equation of state with a correction for obtaining accurate molar volumes, in conjunction with appropriate mixing rules, is coupled to the dynamic conservation equations to obtain a closed system. The boundary conditions are periodic in the streamwise and spanwise directions and of non-reflecting outflow type in the cross-stream direction. Following the DNS protocol, the studied temperature/pressure regime is one where both Kolmogorov and Batchelor scales can be resolved for pseudo-species (i.e., species with transport properties modified to allow the attainment of large enough Reynolds numbers). Correlations for the Schmidt and Prandtl numbers as functions of the thermodynamic variables, based on exact fluid properties, are used to ensure that correct relative transport processes are employed. To obtain rollup and pairing, the layer is perturbed similarly to heptane/nitrogen mixing layers that achieved transition in previous investigations. Due to the strong density stratification, the layer is considerably more difficult to entrain than equivalent initial Reynolds number gaseous, droplet-laden or supercritical heptane/nitrogen layers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2001
- Accession Number
- ADP012368
Entities
People
- Josette Bellan
- Kenneth Harstad
- Nora Okong'o
Organizations
- Jet Propulsion Laboratory