Impinging Jet on a U-Shaped Plate, Heat Transfer, ANSYS Fluent Simulation

Heat Transfer Simulation for Impinging Jets on a U-Shaped Plate using ANSYS Fluent: An Overview

Project Description

This work uses ANSys Fluent for the simulation to examine the heat transport characteristics of an impinging jet on a U-shaped plate.  Effective heat transmission properties of impinging jets are widely used in many different industrial uses including ventilation and cooling.  This work is to investigate convection heat transfer behavior in particular respect to Reynolds numbers and investigate how heat transfer rates are affected by thermal boundary layer thickness.

Geometry and Meshing

• Geometry Design: developed with Design Modeler utilizing a jet-impacted U-shaped plate.
• Mesh Details: Using hexahedral components totaling 2,700,000, structured meshing with ICEM CFD.

Methodology

• Simulation Setup: Steady-state simulation incorporating a gravity effect of -9.81 m/s² on the fluid, using pressure-based solver in place of incompressible flow assumptions.
• Turbulence Model: SST k-w model to depict turbulence properties.
• Boundary Conditions:
  • Inlet: Velocity inlet at 34.89 m/s; temperature at 298 K.
  • Outlet: Pressure outlet with 0 atm set as gauge pressure.
  • Wall Conditions: Applied on a U-shaped plate and jet wall, flux at 5000 W/m².

Results and Analysis

1. Flow Dynamics:

   • Regions of the impinging jet show free jet, stagnation zone, and later wall jet.
   • Maximum pressure noted at the stationary point the jet passes across to impact the plate.

2. Nusselt Number Analysis:

   • Peak Nusselt number at stagnation increases heat transfer because of minimum boundary layer thickness.
   • Boundary layer thickening outside the stagnation zone causes Nusselt number to drop.
   • The study at many Reynolds numbers—23,000, 14,000, and 40,000—showcases the clear impact on Nusselt number distribution.

3. Induction Vortices and Secondary Peaks:

   • Large-scale vortices during stagnation raise fluid velocity, hence improving heat transfer.
   • Secondary peaks on the Nusselt number curve connected to boundary layer transitional vortex formation.

4. Influence of Geometric Parameters:

   • Heat transfer in the nozzle portion depends on aspect ratio; higher ratios produce better results.
   • Maximum heat transfer found by ideal nozzle-positioning (H/d ratio).