Torque converters are an atypical turbomachinery that recirculates flow from the pump into the turbine, through the stator and back into the pump. This means that there is a very high interaction between the stages and changes to one component, such as the pump impeller, could create an entirely different flow field back into the pump impeller. As a result it has become common practice to mainly rely on stator optimization, although major efficiency improvements can be achieved by optimizing all three components simultaneously.
ADT engineers were tasked to redesign an existing torque converter for a leading automotive manufacturer. The current design performance was used as a reference baseline but specifications regarding the number of blades and input speed were left to ADT’s choice during the optimization.
It is essential during the torque converter design phase to maintain both the pump and turbine head, at the specific volume flow rate and also the inlet and outlet conditions of each component at every design iteration. The risk is that mismatch between the components may cause incidence losses and deteriorate the torque converter performance.
Using TURBOdesign1 the inflow and outflow distribution at each blade row, effectively the spanwise work distribution at the leading edge and trailing edge of each blade, are input in for each component and maintained throughout each and every design iteration. This is a major benefit during the design and optimization process and it allows designers to directly control the hydrodynamic performance of the components.