Impact of Orifice Location on the Mechanical Response of Side and Central Orifice Synthetic Jets

Synthetic jets have been at the focus of a number applications including flow control and thermal management of microelectronics due to their unique characteristics of transferring linear momentum through a flow structure without causing a change in net mass flux. Even though there has been extensive research on central orifice synthetic jets in recent years, side slotted synthetic jets have not yet been fully explored in terms of their mechanical and heat transfer properties. The objective of this paper is to gain more insight on the mechanical properties of the side slotted synthetic jets and to compare them with previously published data on central orifice jets. Three different types of rectangular orifice synthetic jets with 10°, 30° and 60° orifice have been designed and manufactured. The orifices represent the measure of the angular portion occupied by the orifice. Analytical and numerical analyses of those synthetic jets have been performed in terms of the modal characteristics of the diagram and the fluid cavity. Results have been compared with the actuator deflection tests using a laser Vibrometer. It was found out that side slotted synthetic jets lead to a higher actuator deflection and consequently may lead to higher heat transfer enhancement than central orifice jets. Results also demonstrate that 60° orifice has the highest actuator deflection, while 10° orifice results in the smallest actuator deflection and lower heat transfer due to high internal resistance in the cavity.