It seems leaf blowers are everywhere in our neighborhoods, very often disturbingly noisy. There is a need for excellent aerodynamic and aeroacoustics design for such devices.
Three leaf blower configurations were designed using CFturbo: a single-stage design, a dual-stage design, and a contra-rotating design. The goal of the design study is to minimize the rotational speed required to meet the performance targets and minimize the swirl downstream of the nozzle. The design point volume flow rate was set to 500 cfm at 25,000 rpm with a total pressure difference of 3,000 Pascals.
Although the relationship between sound output and rotational speed is not directly proportional, higher rotational speeds often result in remarkably increased noise levels due to higher airflow velocity, higher blade tip speeds, higher frequency noise components, and increased flow instabilities. A robust acoustic design optimization would require extensive simulation and testing. By reducing the downstream swirl, the user has improved directional control over the airflow leaving the device.
