Research on key technologies of heat exchanger design for large-scale continuous high speed wind tunnel

With the increase of the operation power and higher requirement on the fine measurement of the large-scale continuous high speed wind tunnel, higher performance of the wind tunnel heat exchanger is required, which is mainly reflected in the heat transfer and pressure loss performance, temperature field uniformity and flow field perturbation characteris-tics. Based on recent years' research, the key technologies and research results in the design of the large-scale continuous high speed wind tunnel heat exchanger are comprehensively discussed. Firstly, the required characteristics of the wind tunnel heat exchanger are analyzed, and the main factors affecting various performances are summarized. Then the high efficiency low-pressure loss design technology is introduced along with the temperature uniformity control technology and the airflow disturbance control technology. The principles of comprehensive trade-off of the heat transfer efficiency and pressure loss of the heat exchanger are presented. And the influences of the heat transfer core arrangement, cooling water flow and its inlet direction, cross section shape of the heat exchanger segment on the temperature field uniformity are discussed. Finally the flow disturbance characteristics downstream of the heat exchanger under different flow conditions and heat exchanger structures are analyzed.