Analysis of the Exhaust Port using Ansys Fluent
Exhaust Port Challenge
AIM:
we need to compare the solutions for 2 sizes of meshes. The first one should be the baseline mesh and the second one should have a finer mesh on the solid zone and also with inflation layers.and to plot the velocity, temperature, and heat transfer coefficient plots.
1.Conjugate heat transfer analysis:
Conjugate heat transfer corresponds with the combination of heat transfer in solids and heat transfer in fluids. In solids, conduction often dominates whereas, in fluids, convection usually dominates. Conjugate heat transfer is observed in many situations.
For example:
Heat sinks are optimized to combine heat transfer by conduction in the heat sink with the convection in the surrounding fluid.
It can be used for the following reasons:
1.Measurement of heat transfer in solid regions by conduction.
2.Identification of the solid domain fluid parameters.
3.Measurement of both the heat transfer from the solid to the fluid environment.
4. Determine the capacity of the material for heat transfer.
5.Surface temperature calculation and major port area
6.Optimization of heat transfer frequency and refreshment capability improvement.
Conjugate heat transfer Applications:
Effective Heat Transfer:
Efficiently combining heat transfer in fluids and solids is the key to designing effective coolers, heaters, or heat exchangers.
The fluid usually plays the role of energy carrier on large distances. Forced convection is the most common way to achieve a high heat transfer rate. In some applications, the performances are further improved by combining convection with phase change (for example liquid water to vapor phase change).
Even so, solids are also needed, in particular, to separate fluids in a heat exchanger so that fluids exchange energy without being mixed.
Flow and temperature field in a shell-and-tube heat exchanger illustrating heat transfer between two fluids separated by the thin metallic wall.
2.we need to compare the solutions for 2 sizes of meshes.
case-1
The Baseline Mesh
In the following case, a Baseline mesh setup with 27530 nodes and 137981 elements.
Geometry:
Meshed geometry:
Scaled-Residuals:
Temperature-Residual:
Stream-lines:
Pressure-contour:
Temperature-contour:
Meshed profile for velocity:
Velocity-contour:
Meshed profile for Wall Heat transfer coefficient:
Wall-Heat-Transfer-Coefficient:
Temperature-value at Output:
case-2
Finer Mesh on the solid zone and also with inflation layers
In the following case, a refined mesh setup with finer mesh in the solid section and the inflation layer near the connection of the heat transfer area region and with 112946 nodes and 309610 elements.
Geometry
Meshed geometry
Scaled-Residuals:
Temperature-Residual
Stream-lines:
Pressure-contour:
Temperature-contour:
Meshed profile for velocity:
Velocity-contour:
Meshed profile for Wall Heat transfer coefficient:
Wall Heat transfer coefficient:
Temperature-value at Output:
Observations
The following max.vlaues for the parameters have been obtained in the case-1 and case-2
1. From the results above, one can state that refined mesh results in more precise interpolation near the walls
2. In case-2 the calculation of the heat transfer coefficient makes an enormous difference from case-1.
3. verify if the HTC predictions from the simulations are right
By performing a check of grid dependence we can confirm simulation results. When we test for various grid sizes, the effects will be independent of the grid width.
And then
by using equation Formula to calculate Nusselts number,
On what factors does the accuracy of the prediction:
1.The number of elements in the mesh:- Finer mesh offers more accurate performance
2. Inflation layers around the boundary:-Inflation layers providing a body-fitting mesh guarantee precise geometry analysis
3.Accurate fitting of mesh around the geometry:-Mesh must be precisely geometrical around the curvatures
4. Setting share topology:-Mesh should be spherically symmetric to smooth mesh transition in various areas