Torque sensor for supercharger research!

“Ultra Boost”, a three year project, partially funded by the Technology Strategy Board, is aiming to develop a supercharged petrol engine with the same power output and only 35% of the exhaust emissions as a current 5L V8 engine but only of half the size.

With the number of cars, vans and light trucks on the roads expected to double in the next 25 years, there is considerable research in progress aimed at developing new techniques to increase the efficiency and reduce the carbon footprint of existing low carbon vehicles (LCV). Currently, less than one in every thousand of the vehicles on the British roads are pure electric or hybrid with the other nine hundred and ninety nine being powered by an internal combustion engines (ICE), petrol or diesel.

As part of the “Ultra Boost” project, a research team at Imperial College London is developing a new supercharger test rig with the aim of assessing the performance of boosting components to allow smaller, more fuel efficient engines to replace larger, less environmentally friendly types. A key component of the system monitoring the efficiency of the supercharger is a Kistler Smart torque sensor which is able to operate precisely and reliably at high speed.

The key to obtaining accurate, repeatable data is the precise monitoring of all the parameters relating to rig performance. Dr Alessandro Romagnoli explains, “To measure the supercharger performance, we needed to replicate the same layout as the engine. The supercharger is driven by an electric motor which, by a system of gears with different ratios, runs the supercharger up to 24,000 rpm providing up to 50Nm. The Kistler Smart torque sensor is located in one shaft (replicating the engine crankshaft) and by measuring the power supplied by the electric motor and the power consumed by the supercharger it is possible to calculate the supercharger efficiency. There being little point in developing a system that absorbs a significant proportion of the total power output of the engine, especially when the system is running light.”

With its long established expertise in using torque measuring technology in demanding applications, Kistler sensors are widely used whenever precision and long life are demanded.