Numerical hydrodynamic analysis liquid dynamometer for ground run and aircraft piston engine tests

During designs of new internal combustion engines (ICE), modernizing existing ICEs, tuning of fuel systems and ignition systems, the use of dynamometric braking devices provides significant assistance. Such devices can also be used when individually tuned stock internal combustion engines. Many types and designs of such devices are known, including mechanical, electrical and hydrodynamic variants. If an engine torque measuring element is provided in the design of the braking devices, such braking devices are called dynamometers. Most dynamometers are significant in size and weight and are designed for testing, running in and tuning engines with a maximum power of at least 80 hp. and operating speeds of no more than 5000 per minute. Dynamometer stands are also known for high-speed sports engines that take energy from the wheel of a vehicle. The use of dynamometers with rotating elements having a large moment of inertia leads to large errors in tuning. For piston engines of UAVs with a relatively small power of 5-60 hp with operating speed range 4000-10000 per minute the most promising is the use of hydrodynamic braking devices of test and rolling benches. Compared to other devices, they are characterized by smaller dimensions, cost and a wide range of absorbed power. The work includes the design of a liquid dynamometer for testing and tuning the internal combustion engine of an unmanned aerial vehicle with a capacity of up to 100 hp. Optimal geometric parameters of hydrodynamic brake were selected. A three-dimensional solid model of a liquid dynamometer was simulated. A numerical hydrodynamic analysis was carried out with a fixed stator and a movable rotor completely filled with working fluid.