ABSTRACT
Flow visualization has contributed greatly to the development of modern fluid dynamics and has been utilized by such pioneers as O. Reynolds, L. Prandtl, G. I. Taylor, and others. Flow visualization reveals the whole flow and temperature fields and always plays an important role in understanding flow phenomena. This chapter reviews examples of applications of flow visualization techniques to internal flow problems with an emphasis on the physical understanding of complicated flow phenomena. It presents brief historical review of the applications of flow-field visualization in internal flows. The applications of flow visualization techniques to selected internal flow problems are also described, using flow photographs and quoting references according to categories. Internal fluid flows occur in many fluid-handling devices and turbomachines and have great technical importance. Internal flow is an old subject in practical hydraulics. The internal flow problems are further complicated by vortex flow, jets, convective flow, particle flow, mixed-phase flow, and magnetic flow.
