PIN NOZZLE Russian patent published in 2023 - IPC F02K9/97 

FIELD: engine building.

SUBSTANCE: invention can be used to create liquid propellant rocket engines. The pin nozzle includes a round central body made in form of a shaft, along the perimeter of the base of which a torus chamber is installed, which is equipped along its entire perimeter with combustion chambers of a liquid rocket engine installed at its end and parallel to the axis of the round central body. A narrow circular slot is made between the shell of the torus chamber and the round central body. At the same time, the contour of the round central body is profiled by a parabola built between 2 tangents, the 1st of which is drawn at the junction of the contour of the round central body and a narrow circular slot at an angle of inclination relative to the axis of the round central body β_prev=180ψ(λ)/π, where ψ(λ) is the gas-dynamic function, which is determined by the following formula: ψ(λ)=√((k+1)/(k-1))·arctg[√((k+1)/(k-1))·√((λ²-1)/(1-((k-1)/(k+1))·λ²))]-arctg√((λ²-1)/(1-((k-1)/(k+1))·λ²)) (Here λ=√[(k+1)/(k-1)][1-(p_a/p_k)^(k-1)/k] - speed coefficient determined by the degree of expansion of the flow in the nozzle; k - adiabatic coefficient; p_a - gas pressure at the nozzle exit; p_k - pressure in the combustion chamber). The 2nd tangent is drawn at the tip of the pin nozzle at an angle of β_a = 0°÷20° from the axis of the central body. At the same time, at the junction of the contour of the round central body and the wall of the circular slot, a contour break is formed by turning the walls of the annular slot of the torus in the direction opposite to the direction of inclination of the 1st tangent, at an angle of α=(0.25÷0.5)ψ(λ) relative to the perpendicular set at the break point of the curvilinear contour of the round central body.

EFFECT: increase of efficiency of the rocket engine.

1 cl, 7 dwg