Exhaust Port Challenge
CHT analysis:
The contemporary conjugate convective heat transfer model was developed after computers came into wide use in order to substitute the empirical relation of proportionality of heat flux to temperature difference with heat transfer coefficient which was the only tool in theoretical heat convection since the times of Newton. This model, based on a strictly mathematically stated problem, describes the heat transfer between a body and a fluid flowing over or inside it as a result of the interaction of two objects. The physical processes and solutions of the governing equations are considered separately for each object in two subdomains. Matching conditions for these solutions at the interface provide the distributions of temperature and heat flux along the body–flow interface, eliminating the need for a heat transfer coefficient. Moreover, it may be calculated using these data.
Applications of CHT:
Starting from simple examples in the 1960s, the conjugate heat transfer methods have become a more powerful tool for modeling and investigating nature phenomena and engineering systems in different areas ranging from aerospace and nuclear reactors to thermal goods treatment and food processing, from complex procedures in medicine to atmosphere/ocean thermal interaction in meteorology, and from relatively simple units to multistage, nonlinear processes. A detailed review of more than 100 examples of conjugate modeling selected from a list of 200 early and modern publications shows that conjugate methods is now used extensively in a wide range of applications. That also is confirmed by numerous results published after this book appearance (2009) that one may see, for example, at the Web of Science. The applications in specific areas of conjugate heat transfer at periodic boundary conditions and in exchanger ducts are considered in two recent books.
Y+ value:
The y plus value is maintained at with the refined mesh giving the first layer thickness of 5.89mm. the yplus value is maintained as 1 because the result are needed to found on the wall were the no slip condition is applied. this shows that at the wall the velocity is zero due to viscosity.
Simulation part of exhaust manifold:
Geometry:
The geometry imported in the spaceclaim is prepared. The seperate geometry is created for solid and fluid stimulation part. Then the topology is shared between the solid and fluid part so the tranfer of data is occured in the stimulation.
Mesh:
At first the baseline mesh i.e the default meshing generated by the system is used. the stimualtion is done for the baseline mesh. for accurate results we need the refined mesh with certain inflation layers. hence the mesh is refined the inflation layer thickness are calsulated with 1 as y+. with that the total thickness is 0.35mm for 5 layers.
Refined mesh:
inflation layers:
Setup:
In the setup, a steady state, pressure based type solver with energy and viscous model as k-epsilon model is used. THen initialised. The velocity contour is created to check the simulation and a certain numbe of iteration is used and calcalated.
Result:
Scaled Residual:
temperature contuor:
Velocity contour:
Streamline velocity contour:
HTC contour:
