Design of a rotor test stand for use in a compressed test facility
Open Access
- Author:
- Gudall, Casey
- Area of Honors:
- Aerospace Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Mark A Miller, Thesis Supervisor
Kenneth Steven Brentner, Thesis Honors Advisor - Keywords:
- Aerospace
VLRCOE
Rotorcraft - Abstract:
- The goal of this research is to investigate aerodynamic scaling for multi-rotor configurations. By comparing data collected using a reconfigurable rotor test stand in an open-jet anechoic wind tunnel to data from a unique compressed air test facility, a range of aerodynamic scales can be investigated. More specifically, this research project focuses on the design, planning, fabrication, and assembly of a rotor test stand for this compressed test facility to allow this investigation. This test stand and its accompanying instrumentation must collect thrust, RPM, torque, and power data during hover while properly matching Reynolds numbers from full-scale rotors. Also, it must be easily assembled/fabricated in the compressed air test facility to allow for a modicum of rotor types while withstanding expected loads. Testing small-scale models at increased static air pressures enables easier Reynolds number matching to full-scale due to higher fluid density. The compressed air test facility uniquely allows for this high-pressure testing. A major consequence of this advantage is the model structure incurring substantially higher loads and power requirements. Through analytical methods of scaling the rotor based on anticipated test facility conditions, the properly scaled rotor size and hence expected loads and required RPM were determined. The instrumentation was selected to collect data within these ranges. Based on the instrumentation specifications and geometry of the test facility, the main structure of the test stand was designed using primarily 80/20 aluminum extrusion parts to support a horizontal configuration. In the compressed air test facility, the horizontal configuration consists of the rotor spinning with the test facility axially (rotor disc oriented with the test section cylindrical cross-section) rather than radially like in a vertical configuration. This horizontal configuration was selected over an original vertical design due to concerns about facility wall recirculation influencing the collected data. To additionally mitigate these facility wall effects, a minimum of five scaled rotor diameters of spacing from the rotor tip to the facility wall was maintained while considering the scaled rotor size. After initial testing first under atmospheric conditions and then under compressed air conditions, the design will be iterated as necessary to produce improved results. The test apparatus was assembled and will be structurally and functionally evaluated prior to the installation and initial testing within the compressed air facility.