Near field acoustic radiation from ducts

Most fans and propellers are located within ducts aimed at improving their aerodynamic efficiency. This includes, for example, the rotor within a duct of a turbomachine, marine propellers, or small shrouded UAV propellers. When the fan is located far from the open end of the duct (a number of acoustic wavelengths), the radiation from the open end is in the form of propagating duct modes. In this case, the duct has a significant effect on the source radiation, which is reasonably well understood from classical theory. However, as ducts become shorter, the propeller becomes increasingly closer to the open end. In these cases its radiation is neither purely in the form of propagating duct modes, or in open space (free field), but somewhere between the two limits. In these realistic cases, the effect of the duct on the acoustic radiation is much less well understood.

This project is a fundamental study into the radiation from ducts due to acoustic sources at varying distances from the open end. The main objective of the project is to assess and understand the effects of the duct on source radiation and hence assist with duct design for reducing noise. The results from this study will also be of significant importance in the design of ducted propellers. The project will be a combination of analytic, numerical and experimental methods.

The successful PhD candidate will join the Acoustics group at the Institute of sound and Vibration Research (ISVR). The ISVR is recognised as one of the world's leading centres for the investigation of sound and vibration phenomena. Applications are invited from prospective UK candidates with an excellent degree (or an equivalent standard in other qualifications approved by the University) in a relevant mathematics, science or engineering subject. Strong mathematical skills will be an advantage.
The studentship will be fully-funded including paid tuition fees (UK/EU rate). We are fortunate that we are able to pay a tax-free bursary that is significantly greater than the standard rate.