No abstract

No abstract

No abstract

Swirl-recovery vanes (SRVs) enhance propulsive efficiency by converting the rotational kinetic energy in a propeller slipstream into additional thrust. This paper discusses the aerodynamic and aeroacoustic impact of the installation of a set of SRVs downstream of a single-rotating propeller. Experiments were carried out in a large low-speed wind tunnel, whereas simulations were performed by solving the Reynolds-averaged Navier-Stokes equations. Favorable comparisons between the experimental and numerical slipstream data validated the simulations, which predicted a maximum propulsive-efficiency increase of 0.7% with the current design of the SRVs. This can be improved further by optimizing the pitch distribution of the SRVs. The upstream effect of the SRVs on the time-averaged propeller performance was negligible. Yet, small but systematic unsteady propeller loads were measured with a peak-to-peak amplitude of at most 2% of the time-averaged loading, occurring at a frequency corresponding to the five SRV passages during one revolution. The downstream interaction was one order of magnitude stronger, with unsteady loading on the SRVs with a peak-to-peak amplitude of about 20% of the time-averaged load. The interaction mechanisms caused an increase of the tonal noise levels of 3-7 dB, with the noise penalty decreasing with increasing propeller thrust setting.

Takedown policy Please contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim.