Laminar flow wing transition position measurement image processing method based on temperature-sensitive paint technology

Abstract

The invention discloses a laminar flow wing transition position measurement image processing method based on a temperature-sensitive paint technology, and the method comprises the steps: S1, carrying out the image collection, processing the surface of a laminar flow wing through the temperature-sensitive paint technology, marking the preset position of the surface of the processed laminar flow wing, acquiring a background image, a reference image and a test sequence image of the laminar flow wing in the wind tunnel by using a camera; S2, carrying out image registration; S3, performing image processing, and performing conversion and calculation based on the light intensity ratio sequence image and a temperature-sensitive paint calibration coefficient relational expression to obtain a laminar flow wing surface heat flow data image; and S4, judging a transition area and a transition position of the wing surface according to the gradient change of the light intensity ratio or the heat flow along the chordwise direction of the laminar flow wing. The invention provides a laminar flow wing transition position measurement image processing method based on a temperature-sensitive paint technology, which is used for processing temperature-sensitive paint technology image data for laminar flow wing transition position measurement, and can be used for processing to obtain a laminar flow wing transition area and a transition position.

Description

technical field [0001] The invention belongs to the field of image information processing of wind tunnel optical measurement test technology, and in particular relates to a laminar flow wing transition position measurement image processing method based on temperature-sensitive paint technology. Background technique [0002] In order to achieve the goal of saving energy, reducing emissions and increasing the flight range, aircraft aerodynamic drag reduction technology has become a key research object for aerodynamic designers. With the rapid development of aviation industry design technology and manufacturing technology, laminar flow design has gradually become possible. For civil airliners, the laminar flow wing design technology can reduce frictional resistance by about 30%, which in turn can increase cruise efficiency by about 15%. noise. In order to test the laminar flow wing design method and the aerodynamic characteristics of the laminar flow wing, it is necessary to m...

AI Technical Summary

Problems solved by technology

There are many defects in this method: First, because the sensor protruding or recessing on the surface of the wing model will interfere with the surface flow field, which will cause differences in the airflow velocity or flow field structure on the surface of the wing, which will cause surface temperature measurement errors, so the sensor is required Strictly flush with the surface of the wing model, it is difficult to install the sensor

2. To install the temperature sensor, it is necessary to make holes and grooves on the wing model at the installation position and the wiring channel, which increases the difficulty of model design and processing, and increases the cost of model design and processing

3. On thin parts such as the wingtip or the trailing edge of the wing, the temperature sensor may not be installed due to insufficient thickness space, so that the transition position measurement of the above-mentioned area cannot be performed

4. The temperature sensor belongs to the discrete point measurement method, which can only measure several points on the surface of the wing. The spatial resolution is very low, and the accurate transition position of the laminar flow wing cannot be obtained.

[0005] In short, the traditional temperature sensor transition measurement method is difficult to install, has large flow disturbance, high cost of model design and processing, can only perform point measurement, and has low spatial resolution. Optical measurement methods such as phosphorescence heat map and other optical measurement methods have limited application range due to their own inherent defects, and cannot accurately measure the transition position of the wing model

The temperature-sensitive coating method has the advantages of surface measurement, high spatial resolution, difficulty in model design and processing, low cost, no disturbance of incoming flow, and accurate judgment of transition position. However, it has not been applied to the measurement of laminar flow wing transition position. Its related image processing methods urgently need to be established

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