CEAS EuroGNC 2024
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Power Optimisation of Variable-Pitch Propeller for an IC Engine with Variable-RPM
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| S. K. Rohith |
PhD Scholar, Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai 600 036, India. | | Govindarajan Bharath |
Assistant Professor, Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai 600 036, India. | | P. A. Ramakrishna |
Professor, Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai 600 036, India. |
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| Abstract:
The present work studies the effect of a simultaneous variable pitch and variable RPM propeller on the thrust generated and aerodynamic power consumed. The study is motivated by the need for aerodynamic efficiency of vertical takeoff and landing systems, which are required to operate in hover (high thrust, no freestream) and cruise (low thrust, high flight speed) conditions. As all flight conditions considered are axial, a blade element momentum theory (BEMT) analysis was developed and employed to understand the aerodynamic behaviour in both these conditions. The BEMT methodology was validated against multiple propellers and was deemed to be appropriate for this work. For a given thrust condition, there are multiple combinations of RPM and blade pitch, and consequently, a gradient-based non-linear optimization technique was employed to identify the combination of RPM and pitch that results in the lowest power requirement. The current BEMT formulation uses linear aerodynamics, and therefore, to ensure the results obtained are practical, inequality constraints were imposed to limit the lift coefficient seen by the blade sections. It was observed that the optimization strategy was able to successfully predict the inputs (RPM and pitch) for all conditions considered. Studies were performed on the effect of varying RPM and flight speed on thrust and power. It was noted that a change in pitch is aerodynamically more efficient than a change in RPM as the latter results in a significant change in the local dynamic pressure, which increases the drag and the power required.
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| Keywords: UAV; IC engine; VPP; Optimisation |
 View PDF CEAS-GNC-2024-021 |
| S. K. Rohith, Govindarajan Bharath, P. A. Ramakrishna: Power Optimisation of Variable-Pitch Propeller for an IC Engine with Variable-RPM. Proceedings of the 2024 CEAS EuroGNC conference. Bristol, UK. June 2024. CEAS-GNC-2024-021.
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| BibTeX entry:
@Incollection{CEAS-GNC-2024-021,
author = {Rohith, S. K. and Bharath, Govindarajan and Ramakrishna, P. A.},
title = {Power Optimisation of Variable-Pitch Propeller for an IC Engine with Variable-RPM},
booktitle = {Proceedings of the 2024 {CEAS EuroGNC} conference},
address = {Bristol, UK},
month = jun,
year = {2024},
note = {CEAS-GNC-2024-021}
}
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