Improving Hydraulic Efficiency by Controlling Fluid Flow Characteristics

Improving Hydraulic Efficiency by Controlling Fluid Flow Characteristics

Jul 25, 2019

Topics: Manufacturing

Hydraulic equipment design is being influenced by demand for increased sustainability, efficiency and reliability.

The focus on sustainability has led to equipment being designed to maximize efficiency and productivity whilst at the same time targeting to minimize both harmful emissions and noise pollution. As a result, the market has seen a shift towards the development of smaller equipment that is able to deliver higher pressures, resulting in an overall increased power density.

To maximize sustainability, the focus must be on improving both the durability and the efficiency of hydraulic equipment.

The value and definition of efficiency can vary by end use case. Decreasing energy consumption per unit time, decreasing cycle time, increasing work done per amount of fuel, parts produced per electricity used and reducing temperature can all be considered methods of increasing efficiency.

Original equipment manufacturers (OEMs) and end users are therefore looking for every possible way to increase hydraulic efficiency. One such method is to look at increasing efficiency by using a suitably designed hydraulic fluid.

To measure hydraulic fluid efficiency performance across a total hydraulic system, we developed a proprietary test rig to replicate a hydrostatic drive system typical of mobile hydraulic equipment. Candidate fluids are further assessed in whole vehicle field trials conducted under tightly controlled conditions.

Extensive testing has identified a high-performance polymer additive that is able to substantially improve hydraulic energy efficiency. This additive lowers the fluid friction under conditions found in well lubricated contacts. In doing so, it also reduces energy losses that occur when a fluid is forced to change direction, for example, around a pipe bend. To investigate this further, particle image velocimetry (PIV) was used to measure the fluid flow characteristics. The PIV experiment involves adding tracer particles to the fluid and illuminating them using a laser. A high-speed camera captures their movement behavior and allows us to visualize the primary and secondary flows. Primary flow is the major part of the flow and secondary flow is where fluid is moving in a different direction to the primary flow.

Secondary flows cause a loss of fluid momentum resulting in wasted energy and efficiency losses. There are many sources of secondary flow loss in hydraulic equipment where the fluid changes direction such as valves, filters, pipe bends and actuators.

Our View

Energy losses from secondary flows can be minimized by formulating with appropriate additive technology. This can lead to significant improvements in hydraulic efficiency and will also provide greater levels of performance and protection, ultimately impacting on the profitability and bottom line of your hydraulic operations.

Get Lubrizol360 updates in your inbox. Sign up today.