Numerical study on flow and heat transfer characteristics of a novel Tesla valve with improved evaluation method

• Relative pressure drop ratio can erase impact of inlet/outlet section length. • Absolute pressure drop ratio reflects the impact of Tesla valve on entire pipeline. • Novel Tesla valve shows better absolute pressure drop ratio than other types. • Reverse flow in Tesla valve is easier to reach thermal stable state. • Thermal diodicity of Tesla valve is independent of wall or inlet temperature. Tesla valve is check valve with no-moving-part, which cannot completely suppress reverse flow but has better reliability and flexibility than check valve with moving-part. Diodicity is most traditional and typical evaluation method used to evaluate the performance of Tesla valve. However, Diodicity decreases with increase of inlet/outlet section length, which fails to normatively evaluate performance of different Tesla valves. Therefore, standardized evaluation method for Tesla valve is conducive to its further application. In this paper, two improved parameters (Relative pressure drop ratio and Absolute pressure drop ratio) are proposed to make up for defect of Diodicity. Besides, a novel Tesla valve with special tapering/widening structure is designed, analyzed and compared with other type of Tesla valves, which shows superior absolute pressure drop ratio. Influences of multi related factors (inlet/outlet section length, inlet velocity, number of stage, property of fluid) on flow characteristics of fluid inside Tesla valve are investigated based on ANSYS Fluent 19.0 with realizable k-epsilon model and verified by experiments. Heat transfer performance of Tesla valve is also sufficiently studied and maximum temperature difference between forward and reverse flows can be 12.10 K, which has the potential to realize a new way for real-time thermal management.