The article considers a calculation method for the non-stationary thrust of pulsejet ejector nozzle that is based on detonation combustion of gaseous fuel.

To determine initial distributions of the thermodynamic parameters inside the detonation tube was carried out a rapid analysis based on x-t-diagrams of motion of glowing combustion products. For this purpose, the section with transparent walls was connected to the outlet of the tube to register the movement of products of combustion.

Based on obtained images and gas-dynamic and thermodynamic equations the velocity distribution of the combustion products, its density, pressure and temperature required for numerical analysis were calculated. The world literature presents data on distribution of parameters, however they are given only for direct initiation of detonation at the closed end and for chemically "frozen" gas composition. The article presents the interpolation methods of parameters measured at the temperatures of 2500-2800K.

Estimation of the thermodynamic parameters is based on the Chapman-Jouguet theory that the speed of the combustion products directly behind the detonation wave front with respect to the wave front is equal to the speed of sound of these products at a given point. The method of minimizing enthalpy of the final thermodynamic state was used to calculate the equilibrium parameters. Thus, a software package «IVTANTHERMO», which is a database of thermodynamic properties of many individual substances in a wide temperature range, was used.

An integral thrust was numerically calculated according to the ejector nozzle surface. We solved the Navier-Stokes equations using the finite-difference Roe scheme of the second order. The combustion products were considered both as an inert mixture with "frozen" composition and as a mixture in chemical equilibrium with the changing temperature. The comparison with experimental results was made.

The above method can be used for rapid analysis of thermodynamic processes inside a jet engine or other process plants without the use of hard-expensive multicomponent kinetic calculations.

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chapmanjouguet theory nonstationary thrust of pulsejet ejector nozzle combustionppbased movement process plants sound hardexpensive multicomponent kinetic calculationsp chemically frozen gas jet engine xtdiagrams of motion of glowing combustion interpolation methods rapid analysis of thermodynamic processes gasdynamic finitedifference roe scheme calculation method minimizing enthalpy of the final thermodynamic state detonation wave front software images density pressure integral thrust thermodynamic properties

A. Yu. Mikushkin,A. A. Samoilova,G. Y. Bivol,A. E. Korobov,S. V. Golovastov,.Numerical Estimation Method for the NonStationary Thrust of Pulsejet Ejector Nozzle. 0 (6),.

A. Yu. Mikushkin,A. A. Samoilova,G. Y. Bivol,A. E. Korobov,S. V. Golovastov,"Numerical Estimation Method for the NonStationary Thrust of Pulsejet Ejector Nozzle" 0

A. Yu. Mikushkin,A. A. Samoilova,G. Y. Bivol,A. E. Korobov,S. V. Golovastov,"Numerical Estimation Method for the NonStationary Thrust of Pulsejet Ejector Nozzle"