Often an engine should fit into several vehicle applications, requiring that some parts have to be modified to match all package configurations. Driven by such package constraints, an inlet pipe to the water-pump inlet had to be redesigned resulting in a 180 degree coolant direction change in front of the water pump inlet. In the beginning the U-flow shaped design was generating an inhomogeneous and non-uniform inlet flow at the water-pump entry. This will reduce the water-pump efficiency and might cause cavitation at the impeller.
For this case the first-in-industry software tool for fluid flow topology optimization called TOSCA Fluid has been used, coupled with STAR-CCM+. TOSCA Fluid is a new software system for non-parametric fluid flow topology optimization producing an optimized 3D design of the flow region as input for a first CAD design. A possible flow region (design space) has to be defined which connects the inlet and outlet cores and is usually limited by clearance planes to other parts. After standard meshing with STAR-CCM+ the optimization is setup to minimize the backflow intensity by sedimentation and to maximize the velocity magnitude uniformity in the impeller plane. After the optimization, the critical recirculation zone in front of the water-pump impeller and other backflow zones were eliminated and the pressure drop has been also reduced. Furthermore a more homogeneous flow distribution at the water-pump inlet has been reached by the optimization tool.
Benefit for Ford:
TOSCA Fluid is the first commercial software for topological optimization of CFD problems. Now, the CFD engineer may generate an initial design of new CFD optimized parts and give it to the designer. With this first proposal the flow improvements can be investigated helping to understand the local flow physics for further possible fine tuning of the flow with parametric and shape optimization methods. This new workflow is highly efficient, reduces development time and improves result quality. Optimized fluid topology is essential for low emissions engines.