Experimental device for researching influence of roughness on heat transfer of wall surface of spray pipe

Abstract

The invention discloses an experimental device for researching the influence of roughness on heat transfer of the wall surface of a spray pipe. The device comprises a spray pipe shell, a graphite temperature measuring piece, a blocking piece and thermocouples; the spray pipe shell is provided with an inlet and an outlet and is cylindrical and expands from the inlet to the outlet; the graphite temperature measuring piece is of a hollow cylinder structure tightly attached to the inner wall of an outlet section, the graphite temperature measuring piece is evenly divided into n graphite temperature measuring units along the outer wall face of the graphite temperature measuring piece, and the roughness of the surfaces, making contact with fuel gas, of the graphite temperature measuring units is different; the blocking piece is arranged at the outlet end of the spray pipe shell and used for positioning the graphite temperature measuring piece; and the plurality of thermocouples are arranged on the outlet section of the spray pipe shell and are specifically distributed on a plurality of cross sections with different expansion ratios, a plurality of thermocouples with different arrangement depths are arranged on each cross section in a surrounding manner, the multiple thermocouples are used for measuring the change rate of the internal temperature of the wall face of the outlet section of the spray pipe shell along with the working time of an engine, and the method for measuring the heat transfer process of the wall face is provided under the condition of the same fuel gas parameter and different roughness in the spray pipe.

Description

technical field [0001] The invention belongs to the technical field of aerospace engines, and in particular relates to an experimental device for studying the influence of roughness on the heat transfer of nozzle wall surfaces. Background technique [0002] Solid rocket motor is one of the main types of engines for modern rockets, aerospace systems and missile weapons. It is widely used in the field of aerospace technology in various countries. It has the characteristics of simple structure, high reliability and convenient use. However, its working process is extremely complicated. , the interaction of combustion and flow brings a series of thorny problems. The traditional solid rocket motor nozzle is generally designed according to the corresponding expansion ratio according to its flight height, in order to maintain the fully expanded working state of the nozzle during the working process, so as to maximize the utilization of the energy carried by the engine. For the trad...

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Problems solved by technology

[0005] The ablation of the carbonized layer is a process that changes dynamically with the working time of the engine, so its surface roughness is also a process that changes continuously with the working time of the engine. The influence of the flow and heat transfer of the boundary layer between the walls is more obvious. At the same time, it is difficult to ensure the consistency of gas parameters in multiple experiments with the current research methods. In supersonic flow, slight changes in several parameters will affect the experimental results. Results bring uncertainty

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