We have long been using ultrasound to look deep into the ground for mineral deposits or even archaeological remnants, and even to lake a look inside the human body to see our vital components functioning.
University of Sheffield’s Department of Mechanical Engineering, Rob Dwyer-Joyce, Professor of Lubrication Engineering, is the first to apply ultrasound technology to the most vital component in our vehicles, the engine, or more specifically, the pistons in the engine.
Various technological advances have made it possible to increase the efficiency and power of the internal combustion engine significantly over the last few years. One of the methods has been to improve machining to allow for lighter weight oils.
For example, the newest engines in the Toyota line are machined to within 0.001”, or 1/1000”, which makes the use of the new 0W-20 oil possible, while still achieving good lubrication. The lighter oil flows more freely and leads to less friction and drag in the engine, increasing efficiency.
Dwyer-Joyce thinks that even this could be overcompensating, “The energy used by the piston rings alone amounts to around 4p in every litre [~23¢/gal] of fuel – there is a lot at stake in getting the lubrication right.” Still, cylinder lubrication is critical, which requires the proper film of oil to seal the cylinder for compression. Too much oil leads to excessive drag and possible burning, while too little oil leads to compression failure and excessive wear. Both cases suffer efficiency problems
Taking direct measurements in a running engine has been nearly impossible, because of its dynamic nature, so putting sensors in the cylinder, or cutting it open, hasn’t really led to significant advances in our knowledge of how cylinder lubrication actually works.
Dwyer-Joyce’s new ultrasound method could change all that, and he mentions, “Our method will allow engine manufacturers to adjust lubrication levels with confidence and ensure they are using the optimum level for any particular engine, rather than over-lubricating to ensure engine safety,” which, in turn, will help automakers increase the efficiency of their engines.