Thermal Analysis for Diesel Engine Exhaust Manifold with Regard to the Boiling Phenomenon and Compared with Experimental Results

Exhaust manifold with the cooling system is widely used in diesel engines which use turbocharger. The Appropriate solution to check how fluid passing through the manifold, is using the computational fluid dynamics laws. According to this, after 3D modeling of the manifold’s body and make the appropriate meshing, using multiphase flows laws and Rensselaer Polytechnic Institute separation method for sub-cooled boiling at low pressure, the effects of fluid flow within the manifold have been simulated. In order to validate the method used for boiling, matching the results with the experimental results is performed. The information in this study includes the distribution of temperature, pressure, flow through the interior geometry and amount of vapor volume fraction that is created in the manifold. The results showed that in the inlet and outlet of manifold, there is a high temperature focus and consideration of boiling phenomenon instead of single-phase flow assumption, reduced the maximum temperature of these areas. The pressure which is applied to Manifold is caused by the combustion gases and the pressure of the cooling fluid is negligible in comparison with that. By analyzing the result, two critical areas of temperature focus were introduced and adaptation of cracks in the original sample with one of these areas, is indicating the accuracy and quality of the obtained results.