A numerical study has been carried out for slot air jet impingement cooling of horizontal concentric circular cylinders. The slot air jet is situated at the symmetry line of a horizontal cylinder along the gravity vector and impinges on the bottom of the outer cylinder which is designated as θ=0°. The outer cylinder is partially opened at the top with a width of W=30mm and is kept at constant t...

numerical study has been carried out for slot air jet impingement cooling of horizontal concentric circular cylinders. the slot air jet is situated at the symmetry line of a horizontal cylinder along the gravity vector and impinges to the bottom of the outer cylinder which is designated as θ=0°. the outer cylinder is partially opened at the top with width of w=30mm and is kept at constant tempe...

This paper presents a computational investigation of a tangential slot blowing conccpt for generating lateral control forces on an aircraft fuselage forcbody. The effects of varying both the jet width and jet exit velocity for a fixed location slot are analyzed. This work is aimcd at aiding rrscarchcrs in designing future experimental and compm tational models of tangential slot blowing. The pr...

Cooktop burners are widely used nowadays. In cooktop burner design, nozzle efficiency and greenhouse gas(GHG) emissions mainly depend on heat transfer from the premixed flame to the impinging surface. This is a complicated issue depending on the individual and combined effects of various input combustion variables. Optimal operating conditions for sustainable burner design were rarely addressed...

A computational study is conducted to explore the effect of synthetic jet orientation on boundary layer separation control. A six-to-one aspect-ratio rectangular slot is chosen in the current study and streamwise and spanwise orientations of this slot are analyzed. In the first part of this study, the interaction of the jet with an attached laminar boundary layer for both slot configurations is...

We report three-dimensional index-of-refraction measurements in a methane-air slot diffusion flame and a methane-air slot subsonic jet using beam-deflection optical tomography. The horizontal and vertical spatial resolutions are 0.26 and 0.635 mm, respectively. The peak temperature is calculated from the index-of-refraction map for the flame and compared with thermocouple temperature measurements.

To control the flow separation in the compressors, a novel pulsed jet concept without external energy injection is proposed. The new concept designs a slot in the middle of the blade and sets a micro device to switch the slot periodically. Such a structure is expected to generate a pulsed jet by the pressure difference between the pressure side and the suction side of the blade. In order to ana...

This paper deals with the optimization of a synthetic jet actuator parameters in the control flow around the NACA0015 airfoil at two angles of attack: 13° (i.e. the stall angle of NACA0015) and 16° (i.e. the post stall angle of NACA0015) to maximize the aerodynamic performance of the airfoil. Synthetic jet actuator is a zero mass flux-active flow control device that alternately injects and remo...

Experimental measurements and flow visualization of synthetic jets and continuous jets with matched Reynolds numbers are described. Although they have the same profile shape, synthetic jets are wider and slower than matched continuous jets. The synthetic jets are examined at higher Reynolds numbers than previously studied and over a large range of dimensionless stroke lengths. Nomenclature b cr...

The flow mechanism leading to the enhanced performance of a discrete co-flow jet (dCFJ) airfoil is investigated. Flow visualization and DPIV are used to analyze the difference between the flow along discrete jets and over the tabs used for discretization of the slot jet. Results show that the entrainment is uniform over the leading jet as long as the tab size is small enough. The jets expand sp...