Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

Every hydraulic circuit wastes energy. A recent study estimated the average energy efficiency of hydraulic equipment in the US at 21%, wasting energy on the order of 10 billion liters of diesel fuel yearly. Canada can expect to have a similar overall efficiency and proportionate waste of energy. Much of the energy wasted in hydraulic circuits is lost when high pressure flows are throttled by control valves in order to control flow or pressure. A technology that has potential to make a revolutionary change in the efficiency of these circuits is the Switched Inertance Hydraulic Converter (SIHC). Unlike throttling valves, which lose energy when reducing flow or pressure, SIHCs convert a high-pressure, low-flow input into a controlled low-pressure, high-flow output (or vice versa), converting pressure energy into flow energy at high efficiency rather than losing it. If applied across the industry, SIHCs can be expected to make a significant impact in the worldwide consumption of fossil fuel. This grant application is concerned with modeling and optimization of these devices, particularly to do with the complex wave propagation effects that limit their practical implementation.
Switched inertance converters are the hydraulic equivalent to the now-ubiquitous electrical DC-DC switching converters which revolutionized the efficiency of everything from phone chargers to high power battery chargers. SIHCs use the inertia of a fluid flowing through a tube (the “inertance tube”) to efficiently regulate flow or pressure. While the high theoretical efficiency of these converters is attractive, their widespread adoption has been hampered by a number of practical concerns. These include lower than optimal energy efficiency and unacceptably high acoustic noise emissions. The research proposed in this Discovery Grant application will address some of the basic science behind each of these issues.
We will develop and validate new dynamic models for the flow inside the inertance tube, taking into account effects such as cavitation at low pressure, as well as the effect of tapering the tube along its length. Preliminary studies have indicated that significant performance improvements can be achieved by carefully positioning the valves along the length of the inertance tube as well as shaping the tube to create internal reflections. We will use the models developed above to exploit these effects, with the goal of increasing efficiency and reducing noise emission, with the overarching goal of hastening the commercial acceptance of these devices.
I expect that this funding will position our lab at the forefront of this emerging technology, both generating new knowledge and training the next generation of engineers in this exciting field.