Bulging bag type cooling structure for binary spray pipe

Abstract

The invention relates to a bulging bag type cooling structure used for cooling a contraction section, an expansion section and the side wall face of a binary spray pipe. The cooling structure comprising bulging bags is designed. The multiple bulging bags are formed on an upper heat isolation liner through punching, and impact holes are formed in the top ends of the bulging bags. A trapezoid air collecting cavity is formed by each bulging bag and a lower heat isolation liner, wherein the part, on the right side of the bottom of each bulging bag, of the lower heat isolation liner is provided with an air film hole. The upper heat isolation liner and the lower heat isolation liner are connected through welding. When cooling air passes through the bulging bags, convection heat exchange on the cooling air side is enhanced under the flow disturbing action of the bulging bags, the cooling air flows into the trapezoid air collecting cavities through the impact holes in the bulging bags, and impact cooling is formed for the lower heat isolation liner; and after the cooling air is decelerated and pressurized in the trapezoid air collecting cavities, the cooling air flows out of the air film holes and is converged into hot flow, an air film is formed on the inner surface of the lower heat isolation liner, and the lower heat isolation liner is protected. The structure is high in cooling efficiency and is hardly influenced by the main and secondary flow pressure ratio, and cooling structure downstream expanding-direction and axial-direction temperature distribution and transition are uniform; and the cooling air utilization is improved.

Description

technical field [0001] The invention relates to a bulge-type high-efficiency cooling structure on a binary nozzle for cooling the converging section, the expanding section and the side wall. Background technique [0002] With the continuous development of aviation technology, the demand for binary nozzles of advanced engines is becoming increasingly urgent. Compared with the axisymmetric nozzle, the binary nozzle requires a larger cooling area, but the engine provides less cooling gas. In order to keep the wall temperature of the binary nozzle lower than the long-term use temperature of the selected material, it is necessary to design an efficient cooling The structure ensures the safe and reliable operation of the binary nozzle. [0003] In the previous designs of axisymmetric nozzles, the cooling methods were relatively simple and the cooling efficiency was not high. One way is to form such as between the nozzle wall and the heat shield figure 1 In the cooling channel s...

AI Technical Summary

Problems solved by technology

The cooling effect of this cooling structure is greatly affected by the change of the pressure ratio of the primary and secondary flow. In practical applications, the parameters of the primary and secondary flow of the nozzle vary in a large range. This structure cannot guarantee the effective cooling of most of the walls.

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