Scaled model testing of coaxial rotor hub flows

Charles Tierney, David Reich, Nicholas Jaffa, Sven Schmitz

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Rotor hub parasite drag remains a primary obstacle to improving the forward-flight capabilities of helicopters. As part of a rotor hub flow physics project at the Vertical Lift Research Center of Excellence (VLRCOE) at Penn State, this investigation was designed to improve the understanding of the interactional aerodynamics and wake flow physics of counter-rotating coaxial rotor hubs and explore designs for reducing the rotor hub drag factor, KKfefeee. These experiments measured the time-averaged and time-varying drag on four rotor hub designs, each with unique blade stubs. The four shapes tested were the DBLN 526 airfoil, 3.25:1 Rectangle, 4:1 Ellipse, and the novel profile named the Optimized Cambered Shape (OCS). Load data was collected at four Reynolds numbers ranging from 3.77 × 105 to 1.51 × 106 and advance ratios ranging from .25 to .6. Additionally, stereoscopic particle-image velocimetry (SPIV) measured the three velocity components at two downstream locations in the wake of the DBLN 526 rotor hub at RRee = 1.13 × 106 and advance ratios of .25 and .6, providing insight into and visualizing the development of the wake. Presented here is the compiled load data and calculated KKfefee from these experiments, as well as the flow fields at the near- and mid-wake locations, with discussion of new knowledge gained of the coaxial rotor hub wakes.

Original languageEnglish (US)
Title of host publication77th Annual Vertical Flight Society Forum and Technology Display, FORUM 2021
Subtitle of host publicationThe Future of Vertical Flight
PublisherVertical Flight Society
ISBN (Electronic)9781713830016
StatePublished - 2021
Event77th Annual Vertical Flight Society Forum and Technology Display: The Future of Vertical Flight, FORUM 2021 - Virtual, Online
Duration: May 10 2021May 14 2021

Publication series

Name77th Annual Vertical Flight Society Forum and Technology Display, FORUM 2021: The Future of Vertical Flight

Conference

Conference77th Annual Vertical Flight Society Forum and Technology Display: The Future of Vertical Flight, FORUM 2021
CityVirtual, Online
Period5/10/215/14/21

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Control and Systems Engineering

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