Thermal insulation system of free jet dynamometric test model

Abstract

The invention discloses a novel thermal insulation system for a free jet flow force measuring test model. The novel thermal insulation system includes a force measuring balance, a supporting rod, a balance protection cover, a thermal insulation assembly and a gas cooling assembly; the force measuring balance is arranged in a mould inner cavity; one end of the force measuring balance is connected with the mould inner cavity; one end of the supporting rod is connected with the other end of the force measuring balance; the balance protection cover is arranged on the force measuring balance in a covering manner so as to realize thermal insulation protection for the force measuring balance; the thermal insulation assembly includes a thermal insulation sleeve which is arranged along the circumferential direction of the supporting rod; a sealing space is defined between the thermal insulation sleeve and the outer circumferential surface of the supporting rod; labyrinth seal components are arranged on the supporting rod at intervals so as to divide the sealing space into at least three intervals; and the gas cooling assembly includes gas jetting rings which are located in the intervals and sleeve the outer circumference of the supporting rod, and a cold gas pipeline which is communicated with the gas jetting rings, wherein the cold gas pipeline is connected with a high-pressure cold gas source, and the gas jetting rings jet out a cooling gas to decrease the temperature of the mould inner cavity. According to the novel thermal insulation system of the invention, a plurality of thermal insulation and cooling means are adopted, and therefore, the novel thermal insulation system is remarkable in cooling effect and compact in structure, and can effectively control the temperature of the balance.

Description

technical field [0001] The invention relates to wind tunnel test equipment, and more particularly, the invention relates to a thermal insulation system for a model of a free-jet dynamometric test. Background technique [0002] With the continuous development of my country's aerospace technology and the needs of national strategies, hypersonic vehicles have gradually become the focus of national aerospace development. Different from conventional low-speed aircraft, hypersonic flight has time scale, Reynolds number, temperature, and thermochemical effects. Wind tunnel tests need to simulate airflow speeds above Mach 5, high temperatures around 2000K, and characteristic times that satisfy temperature effects. scale. The free-jet wind tunnel can provide high-speed reverse heated airflow to simulate the typical hypersonic flight environment, and solve the influence of the comprehensive mechanical environment during the flight process on the aerodynamic characteristics of the air...

AI Technical Summary

Problems solved by technology

Because the model and the force measuring system are in the high-temperature airflow for a long time, the temperature of the model and the balance will inevitably increase continuously. Excessively high temperature will cause a large temperature drift of the balance strain gauge, resulting in serious distortion of the force measurement data and even damage the balance. Strain gauges caused the test to fail

Since work on dynamometric tests in free jets has not been carried out very long, no standardized thermal insulation cooling system is available

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