Маршевые алгоритмы расчета термогазодинамических процессов в прямоточных воздушно-реактивных двигателях, интегрированных с летательным аппаратом, с учетом пространственных эффектов

A description of the calculation and methodological support for carrying out operational complex calculations of thermogasdynamic processes in the elements of a ramjet engine integrated with the body of the aircraft, by marching methods in a three-dimensional approximation is given. Numerical simulation of the flow around an aircraft with a ramjet engine is broken down into four components: flow around tip and side surface of an aircraft body, calculation of the flow in the air intake device, the combustion chamber, the nozzle and the exhaust jet flowing around the tail section of the aircraft body. The supersonic flows around the body of the aircraft and the flow in the intake device are calculated in the non-viscous approximation using the Godunov scheme or taking into account the viscosity using the “viscous layer” model. The current is calculated using the “narrow channel” model in the region of subsonic flow in the outlet part of the air intake device. The same model is used in the calculation of subsonic no equilibrium flow of combustion products in the combustion chamber. The flow in the exhaust jet is calculated taking into account the flow past the lower tail section of the aircraft and the interaction of the jet of combustion products with a disturbed mainstream air. Kerosene is used as a fuel in the combustion chamber of a ramjet engine. A two-stage mechanism is used with kerosene ignition during oxidation and modeling of the burning of kerosene combustion products in elementary chemical reactions for C–O–H mixtures when calculating the flow parameters in the combustion chamber. The proposed technique can be used at the preliminary design stage of a ramjet. The use of mathematical models developed at the ITM of NASU and SSAU and the corresponding computational and methodological support allows carrying out operational complex calculations when choosing the design parameters of an aircraft with a ramjet engine