Isothermal and Isobaric Humidification Control System and Control Method for Large Icing Wind Tunnel Circuit

Abstract

The invention discloses an isothermal and isobaric humidification control system and control method for a large-scale icing wind tunnel circuit, belonging to the technical field of icing and anti-icing tests. According to the test requirements, the wind tunnel power system, refrigeration system, and height simulation System, so that the airflow field, temperature field, and wall static pressure in the test section all reach the set value; at the same time, the humidification control system is ready, and the dry steam is sent to the humidity closed-loop control system; before starting the spray system to simulate the cloud and fog field, start the humidity closed-loop control System and multi-channel pressure closed-loop variable structure PID control strategy, so that multiple channels of steam are sprayed from the nozzles of the airfoil spray rack at equal pressure, so that the water vapor can be quickly and evenly mixed with the high-speed airflow in the wind tunnel, so that the icing wind tunnel The humidity of the body circuit quickly reaches the set value; restart the spray system to simulate the cloud and fog field, no longer affect the liquid water content and particle size of the cloud and fog field due to air humidity, and truly simulate the icing environmental parameters to improve the accuracy of the test results.

Description

technical field [0001] The invention relates to the field of wind tunnel tests, in particular to a control system and method for isothermal and isobaric humidification of a circuit in a large icing wind tunnel. Background technique [0002] The icing wind tunnel is an important special test facility for researching and evaluating icing and anti-icing problems of aviation aircraft. The high-altitude low Reynolds number test plays an important role in national economy and national defense construction. During the icing wind tunnel test, the liquid water content is an important technical index of the cloud and fog field, and the air humidity in the tunnel directly affects the liquid water content. When the relative humidity is too low, part of the water sprayed by the spray system will evaporate, and the liquid water content will decrease. When it is oversaturated, excess water vapor will condense out of it, which will directly affect the liquid water content and The particle...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the current large-scale icing wind tunnel needs fast isobaric and isothermal humidification in the wind tunnel test process. For the large humidification section, the pressure closed-loop control is adopted for the horizontal steam pipelines with different height differences to realize multi-channel The steam is sprayed out from the nozzles of the airfoil spray rack at equal pressure to ensure rapid, uniform and stable humidification of the large section of the cave circuit, so that the air humidity of the cave circuit can quickly reach the set value, and the parameters of the icing environment are truly simulated to ensure the accuracy of the test results. authenticity and validity

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