Thermal Wave Applications in Flow Fields With Steady Velocity Profile

This study explores the use of a thermal wave approach for flow field measurement applications, such as flow diagnostics near surfaces and in microfluidic systems. The basic mathematical characteristics of the governing equations of heat convection, with periodic heating boundary conditions in steady flow, are discussed and the validity of applying the complex combination method to this problem is illustrated. A scaling analysis of a two-dimensional thermal wave configuration with a linear velocity profile is performed to provide important insights into this type of heat transfer phenomena. A two-dimensional conjugate heat transfer model is developed and solved numerically with a finite difference method to demonstrate an example of imposing a thermal wave onto a flow field. The simulation results show that the temperature signal, especially the phase information, can be used for the measurement of flow properties near the surface, such as the wall shear stress.