Annular supersonic velocity spray pipe and design method thereof

Abstract

The invention provides an annular supersonic velocity spray pipe and a design method thereof. The design method for the annular supersonic velocity spray pipe comprises the following steps of: predicting a flow field parameter in a transonic velocity segment area, and extracting an initial characteristic line from the flow field parameter; determining the mach number distribution of a supersonic velocity upright wall of the spray pipe according to design requirements; and determining a supersonic velocity curved wall molded surface of the spray pipe by a characteristic line method according to the initial characteristic line and the mach number distribution of the supersonic velocity upright wall. According to the design method for the annular supersonic velocity spray pipe, compression waves are not concentrated in a flow field of the designed annular supersonic velocity spray pipe, the distribution of the flow field parameter can be optimized according to actual application, and thequality of the flow field of the annular supersonic velocity spray pipe can be greatly improved. According to the annular supersonic velocity spray pipe, the design method for the annular supersonic velocity spray pipe is utilized.

Description

technical field [0001] The invention relates to the field of fluid power, in particular to an annular supersonic nozzle and a design method thereof. Background technique [0002] Supersonic nozzles are widely used in high-speed aircraft, rockets, supersonic wind tunnels, high-energy lasers, ejector vacuum pumps and other equipment. The quality of the nozzle flow field has an important impact on the performance of the equipment. Obtaining an appropriate nozzle wall curve through certain design techniques can greatly improve the quality of the nozzle flow field, improve equipment performance, and save research funds. The supersonic nozzle is generally composed of a constriction section and an expansion section. Driven by a certain pressure, the gas gradually accelerates in the constriction section and reaches the speed of sound near the throat, and then continues to accelerate in the expansion section until the required Mach number and flow are formed at the outlet. Supersoni...

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Problems solved by technology

This geometrically complex relationship makes the expansion characteristics of the annular flow channel different from that of two-dimensional or circular pipes, so the acceleration characteristics of the gas are also different. This particularity of geometry and flow structure brings certain limitations to the design method. difficulty

Although there are a variety of relatively mature two-dimensional or axisymmetric nozzle design methods, which can achieve high outlet flow field quality, the existing methods cannot be directly extended to the design of the annular nozzle profile curve.

The main problems it faces include: 1. The existing flow models and empirical formulas are difficult to apply directly; Third, the correction of the boundary layer on the annular wall is also different from that of the axisymmetric wind tunnel nozzle

U.S. Patent No. 3940067 proposes a plug-type nozzle for rocket engines, which is actually an annular nozzle. Its design goal is to achieve the shortest length under the premise of ensuring the pressure difference between the combustion chamber and the outside world. The invention mainly focuses on the structure The design of the nozzle has been improved from the perspective of heat resistance and material performance, and the curve of the plug cone and the outer wall of the nozzle is designed according to the principle of ballistic optimization. The curve designed by this method cannot guarantee the Mach number of the flow field and the flow direction angle. Uniformity, it is also difficult to solve problems such as wave clipping and viscosity correction in the supersonic region

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