Heat transfer in chambers at accelerated moving piston

摘要

Numerical results of turbulent heat transfer of thermal ionized gaseous mixture in chamber behind the accelerating piston are presented by the model considering the thermal and dynamic inertia of working continuum, the nonstationary of turbulent structure, the interference of chemical reactions and turbulence, variability of gaseous thermophysical properties which are determinated within the bounds of multicomponent media. The total mathematical problem definition included the Reynolds dynamic equations written in the "narrow channel" approximation, the energy equation at enthalpy form, equations of the continuity, the state equation and the heat conduction equation for chamber wall. For determining the turbulent transfer coefficients of momentum and heat the turbulence multi- parametric model, including the transport equations for Reynolds shear stresses and scalar substation fluxes, autocorrelations of enthalpy fluctuations, as well as the closuring relations, such as the base of the differential equations for turbulence kinetic energy and its integral scale is utilized. For unknown terms of higher order the modeling closures are written originally in view of wall effects. It permits to accomplish the calculations in total flow field up to the chamber wall, including the laminar sublayer and the buffer zone. In the paper the structure of inert and chemically reacting flow behind the moving piston, the flow features connected with the influence of chemical reactions, non-stationary heat transfer are analyzed in detail.