High-altitude propeller low-density wind tunnel test system and method

Abstract

The invention discloses a high-altitude low-density wind tunnel test system and method. The system comprises a low-density wind tunnel; a propeller unit is arranged in the low-density wind tunnel, andthe central axis of the test propeller coincides with the central axis of the low-density wind tunnel; a control unit is used for controlling atmospheric parameters and test state parameters of a wind tunnel test in the low-density wind tunnel; and a data acquisition unit is used for acquiring test data. Atmospheric parameters of a wind tunnel test of the low-density wind tunnel are controlled through the control unit, so that atmospheric environments from the sea level to different high altitudes are tested in the low-density wind tunnel; the control unit further controls the flight rotatingspeed of the propeller, and wind tunnel test state data are collected through the collection unit, so that the high-altitude aerodynamic performance of the propeller can be accurately tested. The system and method can be used for similar high-altitude propeller tests.

Description

technical field [0001] The invention belongs to the field of flight test technology, and more specifically relates to a high-altitude propeller low-density wind tunnel test system and method. Background technique [0002] The flying height of solar-powered drones in near space is between 0km and 30km, and the flying speed ranges from 8m / s to 70m / s. It has the characteristics of large flying height and speed span. The propeller as its main power device is in a high-altitude low-density working environment. The density of the atmosphere at a height of 20km is about 1 / 14 of sea level, and the pressure is about 1 / 18, showing low density and low Reynolds number effect. In order to provide enough thrust for the aircraft to maintain its high-altitude flight, the adjacent space propeller is larger than the conventional aircraft propeller, and even at a relatively low speed, the tip Mach number is relatively large. In addition, since most of the thrust of the propeller is provided b...

AI Technical Summary

Problems solved by technology

However, the test method based on the similarity criterion of equal forward ratio and equal Reynolds number requires extremely low incoming flow velocity. It is difficult to guarantee the quality of the flow field when the wind speed is lower than 8m / s in domestic low-speed wind tunnels. The higher the flight state altitude, the corresponding test The smaller the value of state speed, rotational speed, pulling force and torque, the greater the relative measurement error, making it difficult to accurately measure propeller aerodynamic performance data

Conventional ground vehicle tests are susceptible to interference from factors such as external wind and ground road conditions, which will have a certain impact on the test results

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