Transient Thrust Analysis of Rigid Rotors in Forward Flight

Travis Krebs,Goetz Bramesfeld,Julia Cole

doi:10.3390/aerospace9010028

Travis Krebs, Goetz Bramesfeld + Show 1 more

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https://doi.org/10.3390/aerospace9010028

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Abstract

The purpose of this study was to investigate and quantify the transient thrust response of two small rigid rotors in forward flight. This was accomplished using a distributed doublet-based potential flow method, which was validated against wind-tunnel experimentation and a transient CFD analysis. The investigation showed that for both rotors, advancing and retreating blade effects were predicted to contribute to transient thrust amplitudes of 5–30% of the mean rotor thrust. The thrust output amplitudes of individual rotors blades were observed to be 15–45% of the mean rotor thrust, indicating that it is not uncommon for the thrust output variation of an individual rotor blade to approach the same value as the mean thrust output of the rotor itself. In addition to this, the theoretical analysis also illustrated that higher blade thrust oscillations resulted in pronounced asymmetric rotor wake structures.

Highlights

The purpose of this study is to investigate and quantify the transient thrust response of small rigid rotors in forward flight under various operating conditions through numerical predictions of unsteady blade and wake effects
The purpose of this research was to quantify the transient thrust output of rigid purpose this research was tomodeling quantifysubstantiated the transientthrough thrust output of rigid rotors in The forward flight,ofusing computational wind-tunnel rotors in forward flight, using computational modeling which was substantiated through experimentation and CFD
The potential-flow based computathis study is based on distributed doublet elements (DDEs) and is well-suited to unsteady tion model used inwakes

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Citation: Krebs, T.; Bramesfeld, G.; Cole, J. Transient Thrust Analysis ofRigid Rotors in Forward Flight.Aerospace 2022, 9, 28. https://doi.org/10.3390/aerospace9010028Academic Editor: Haixin ChenReceived: 6 December 2021Accepted: 28 December 2021Published: 5 January 2022Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.Licensee MDPI, Basel, Switzerland.Attribution (CC BY) license (https://

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