Jet vectoring using synthetic jets

Abstract

The interaction between a conventional rectangular (primary) air jet and a co-flowing synthetic jet is investigated experimentally. The nozzles of both jets have the same long dimension but the aspect ratio of the synthetic jet orifice is 25 times larger. Detailed particle image velocimetry (PIV) measurements of the flow in the midspan plane show that primary jet fluid is directed into the synthetic jet orifice and the interaction between the jets leads to the formation of a closed recirculating flow domain. The concomitant formation of a low-pressure region between the jets results in deflection of the primary jet toward the actuator jet despite the absence of an extended control surface (e.g. a diffuser or collar) and is balanced by a force on the primary jet conduit. For a given synthetic jet strength and primary jet speed, the vectoring force depends mainly on the volume flow rate of primary jet fluid that is diverted into the synthetic jet actuator. This flow rate is regulated by restricting the flow of entrained ambient fluid using a small streamwise extension of the synthetic jet orifice that scales with the orifice width. The response of the primary jet to the imposed vectoring is investigated using stepped modulation of the driving signal. The characteristic vectoring time and vectoring angle decrease monotonically with primary jet speed.

Vectoring of parallel synthetic jets: a parametric study

“…A large operational difference between continuous and synthetic jets is that the latter do not need an external fluid supply and therefore can be easily integrated in complex geometries, making them attractive actuators for flow control. Applications of synthetic jets, such as separation control (Dandois et al 2007), turbulent boundary layer control (Rathnasingham & Breuer 2003;Canton et al 2016), virtual aeroshaping (Mittal & Rampunggoon 2002), thrust vectoring (Smith & Glezer 2002;Luo & Xia 2005), heat transfer (Persoons et al 2009) or propulsion (Athanassiadis & Hart 2016), include, but are not limited to, applications with a crossflow. For most of these applications, the specific direction of the synthetic jet is important.…”

Axisymmetric Coanda-assisted vectoring

“…Other fluidic jet vectoring schemes may not require Coanda surfaces, but typically require larger control flows and combinations of blowing and suction such as demonstrated by Smith and Glezer [6], Bettridge et al [7], and Hammond and Redekopp [8]. Vectoring using a Coanda surface and a synthetic jet control was demonstrated by Pack and Seifert [9].…”

Numerical investigation of the influence of nozzle geometrical parameters on thrust of synthetic jet underwater

“…These experiments demonstrated the importance of vortex ring pinch off in self-propelled vehicles. Synthetic jet in air is also intensively researched [15][16][17][18][19][20][21][22]. The geometrical parameters have a great effect on its fluidic characteristic.…”