A new approach called "venturi flow cooling concept" is described. Single phase fluid flow in a circular tube is forced through a short annular throat section creating high velocity in order to enhance wall heat transfer. Experiments were performed in a 3.33 cm dia. test section with water. Results show a three to four-fold increase in average wall-to-fluid heat transfer coefficient for the venturi flow compared to the circular flow. This concept has a potential application in cooling solid state switching devices such as MCTs which have power dissipation of the order of 200 W/cm2.