Supersonic velocity axisymmetrical boundary layer wind tunnel

Abstract

The invention provides a supersonic velocity axisymmetrical boundary layer wind tunnel which comprises a front transition section (1), a stabilizing section (2) and a spray pipe experiment section (3), wherein the front transition section (1) is used for introducing air flows and carrying out primary rectification on the air flows; the stabilizing section (2) is connected to the downstream of the transition section (1) and used for carrying out secondary rectification on the air flows; the spray pipe experiment section (3) is connected to the downstream of the stabilizing section (2) and is in a fan-shaped axisymmetrical structure relative to a rotation axis (O); the spray pipe experiment section (3) comprises an outer peripheral wall (3a), an inner peripheral wall (3b) and two side walls (3c and 3d) connected with the outer peripheral wall (3a) and the inner peripheral wall (3b); transparent windows are at least formed on the side walls; the spray pipe experiment section (3) also comprises a spray pipe part (31) which is in a single-side expansion spray pipe structure and an experiment part (32) which is positioned on the downstream of the spray pipe part and can be used for carrying out observation and an optical non-contact test on an axisymmetrical boundary layer flow field formed in a spray pipe experiment section so as to research the flow field characteristics of the supersonic velocity boundary layer.

Description

technical field [0001] The invention relates to a wind tunnel, in particular to a supersonic axisymmetric boundary layer wind tunnel. Background technique [0002] With the development of modern aerodynamic technology, the study of aerodynamic mechanism is becoming more and more important. As a typical compressible shear flow, the study of supersonic boundary layer not only has a wide application background but also has important theoretical significance, such as axisymmetric aircraft The dynamic performance of the aerodynamic control and axisymmetric engine. The fine structure of the boundary layer flow field with spanwise curvature remains to be further studied. More than 100 years of boundary layer research has shown that there are still a large number of unrecognized problems in the boundary layer, especially in the supersonic boundary layer. Serious challenges. Experimental research on the supersonic boundary layer needs to be carried out in depth. [0003] The supe...

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Problems solved by technology

[0008] The main problems of the model-based boundary layer experimental research method are as follows: 1. The front edge of the conical boundary layer in the supersonic flow field will inevitably generate shock waves, which will interact with the boundary layer after being reflected by the wall or free jet boundary, resulting in The complex flow field structure is not conducive to the study of the fine structure of the boundary layer; second, because the wind tunnel is not designed for the boundary layer research, the corresponding experimental cabin is generally large, which is not conducive to the use of optical non-contact testing technology to study the boundary layer. Third, some down-blowing wind tunnels have relatively large Reynolds numbers, and the flow field has not been treated for noise reduction, which seriously affects the transition and instability characteristics of the boundary layer, which is not conducive to mechanism research

[0009] The boundary layer generated by the wall of the wind tunnel is directly used for research. Although the problem of shock wave interference is overcome, it is difficult to observe the boundary layer inside the nozzle by optical means, which is very unfavorable for the study of the influence of the upstream flow field structure on the boundary layer.

In addition, the development of the boundary layer on the two side walls of the existing wind tunnel seriously interferes with the flow field structure of the main boundary layer, which is also not conducive to the mechanism research

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