Experimental and numerical study of effect of secondary surfaces fixed over rectangular vortex generator with an overview of dynamic mode decomposition

Abstract

Addition of a vortex generator (VG) to the heated surface creates longitudinal vortices in the flow; however, it induces drag. Surface modification of the VG may play a role in the thermal performance of the system. Therefore, flow and thermal behavior are studied for a secondary surface (SS) attached to the primary surface of a rectangular VG, which is placed inside a rectangular channel using air at Re = 5000. The VG with the SS is compared with a conventional rectangular VG having volume constant. With the addition of SS, the flow behind the VG greatly shears the produced primary vortex (P), which results in stretching. Stretching increases the angular momentum of the vortex with the decrease in the span of the produced vortices. The interaction between the co-rotating vortices P and high pressure side horse-shoe vortex (Hp) shows that the higher strain field induced by the vortex P shears away the vortex Hp. The vortex P developed under the influence of SS induces a higher degree of tilting toward the heated surface with low propagation speed. Finally, the dynamic decomposition of the vortices in the channel reveals that the vortex P appears to be dominant.

Current Review on Numerical Simulation of Synthetic Jet (SJ) Cooling

“…Type of flow Turbulence model Chen et al, [10] ANSYS Fluent PISO -k-omega SST D' Alencon et al, [11] ANSYS Fluent SIMPLE Transient conventional k-SST Benayad et al, [14] ANSYS Fluent -Transient, incompressible k-omega SST Huang et al, [16] ANSYS Fluent SIMPLE Incompressible k-omega SST Mohammadshahi et al, [19] -SIMPLE Incompressible k-omega SST Li et al, [22] --Transient, incompressible, k-turbulence SST Yeom et al, [52] ANSYS Fluent SIMPLE Incompressible k-omega SST Rulik and Wroblewski [24] ANSYS Fluent Transient, compressible k-omega SST Lau et al, [25] -SIMPLE Incompressible -Kumar et al, [27] ANSYS Fluent SIMPLE Transient, incompressible -Qiu et al, [34] -SIMPLEC Transient, incompressible -Tan et al, [37] ANSYS Fluent SIMPLE Incompressible k-turbulence SST Geng et al, [42] ANSYS Fluent PISO Transient, incompressible k-omega SST Fisher et al, [43] ANSYS Fluent PISO, SIMPLE Transient, steady k-turbulence SST Hoh et al, [44] ANSYS Fluent PISO Transient, incompressible -…”

“…The thermal and hydrodynamic impacts of Nano-fluid flows were found to be greatly underestimated by the homogeneous (single-phase) model. Kashyap et al, [42] researches the impact of secondary surfaces (SS) fixed over a rectangular VG while providing a summary of dynamic mode decomposition. When SS is present, the flow behind the VG significantly shears the generated primary vortex, causing it to stretch.…”