How ADT Engineers Design and Optimize an Automotive Torque Converter

Torque converters are quite atypical turbomachinery, they feature recirculating 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. It has become common practice to mainly rely on stator optimization, although major efficiency improvements can be achieved by optimizing all three components simultaneously.

AnyConv.com__Torque Converter

Fig. 1. Torque Converter.


For this project, ADT engineers were tasked to redesign an existing torque converter for a leading automotive manufacturer. The existing 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 a 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.


What is blade loading?


A first design using TURBOdesign1 was generated as a starting point for the optimization, where the design input parameters followed the generally established design guidelines illustrated below.


TURBOdesign1 - Automotive Torque Converter

Fig. 2. Streamwise loading used for the baseline stator, pump and turbine respectively.


The stator features a mid-loaded distribution, while the pump is clearly aft-loaded to reduce profile losses. The turbine features a fore-loaded hub and aft-loaded shroud to control secondary flows.

To see the results of the initial design and the optimization of the entire torque converter, we invite you to download your free copy of this consultancy summary below:

Download the consultancy summary

Book a LIVE demo on the design of a turbomachinery application of your choice.

Our demo is tailored to your specific application and design challenges

Book a Demonstration

Mehrdad Zangeneh

Mehrdad Zangeneh is Founder and Managing Director of Advanced Design Technology and professor of Thermofluids at University College London.

View All Articles


How to Optimize the Efficiency and Cavitation of High Speed Centrifugal Pumps?

Franklin Electric is a global leader in the manufacturing and distribution of products and systems focused on the movement and management of water...

How to Redesign a Compressor Stage for a High-Performance Electric Supercharger in a Heavily Downsized Engine

Recently, automotive companies have shown a large investment and push toward downsizing automotive gasoline and diesel fueled engines. The drive...

What are the Difficulties of Taking a Traditional and Direct Design Approach?

There are two main approaches to the problem of aerodynamic design of turbomachinery blades, the direct and the inverse approach. In the direct...