关键词: 波纹壁面, Ledinegg不稳定性, 流动不稳定起始点, 微细通道

Abstract: In order to explore the Ledinegg instability of the micro-channels of different corrugated wall surfaces, computer numerical control was used to process three types of micro-channels of wall surfaces, namely sine wave, triangle wave and ordinary smooth micro-channels. R141b was used as the experimental working medium to conduct the flow heat transfer experiment under the conditions of pressure of 40kPa~80kPa, heat flux of 13.281kW/m2~22.138 kW/m2 and inlet temperature of 33℃. The experimental results show that the negative slope of pressure drop-flow curve in triangular ripple micro channel has the lowest slope, and the mass flow at the onset of flow instability (OFI) is the largest, and Ledinegg instability is most likely to occur, while the normal smooth micro channel is the opposite. In addition, with the increase of heat flux, the slope of the negative slope region of the pressure drop-flow curve of the micro channel decreases, and the mass flow at OFI increases, indicating that the increase of heat flux will increase the instability of the system. With the increase of system pressure, the negative slope area of pressure drop-flow curve of the micro channel became gentler, while the mass flow at OFI did not change much, indicating that increasing system pressure was beneficial to the stability of the system.

Key words: corrugated wall, Ledinegg instability, starting point of flow instability, micro-channels