Keywords: gravity draught, rocket motors, solar power plants, unsteady flows, computational fluid dynamics, CFD, space engines, solar towers, solar energy, discontinuous flows, simulation, wave front modelling, gas dynamics
Technology of Computational Fluid Dynamics in space engines and solar-gravity draught power plants
Non-isentropic discontinuous, unsteady flows with energy addition or extraction, during ignition of solid propellant rocket motors or tall solar towers heating transients are approached through a wave front method, initially developed by Zannetti for isentropic flows in aerodynamics. Its application in discontinuous flows with zones of different behaviour and energy extraction proves highly efficient. Computational efficiency is demonstrated by Computational Fluid Dynamics simulation of the starting transients in ADDA Solid Rocket Engines (SRE) and in the SEATTLER solar mirror tower. The code is exclusively directed to unsteady flow simulations in slender channels. The wave front model scheme covers the dual behaviour of fully non-isentropic flow with mass addition and mixing in the thrust chamber or blunt heat addition in a heater and fully isentropic through the exhaust nozzle or gravity draught in a tall tower. Along the tower of the solar-gravity draught power plants, small perturbation discontinuous flows are covered. Code robustness is demonstrated during runs on the PC. The 1D numerical scheme is based on the resolution of gasdynamic discontinuities within the enhanced method of Zannetti.