Accession Number : AD1029037

Title :   A Dynamic Calibration Method for Experimental and Analytical Hub Load Comparison

Descriptive Note : Technical Report,01 Jan 2014,31 Dec 2015

Corporate Author : US Army Research Laboratory Aberdeen Proving Ground United States

Personal Author(s) : Thornburgh,Robert P ; Kreshock,Andrew R ; Wilbur,Matthew L

Full Text :

Report Date : 01 Mar 2017

Pagination or Media Count : 20

Abstract : This report presents the results from an ongoing effort to produce improved correlation between analytical hub force and moment prediction and those measured during wind-tunnel testing on the Aeroelastic Rotor Experimental System (ARES), a conventional rotor testbed commonly used at the Langley Transonic Dynamics Tunnel (TDT). A frequency-dependent transformation between loads at the rotor hub and outputs of the testbed balance is produced from frequency response functions measured during vibration testing of the system. The resulting transformation is used as a dynamic calibration of the balance to transform hub loads predicted by comprehensive analysis into predicted balance outputs. In addition to detailing the transformation process, this report also presents a set of wind-tunnel test cases, with comparisons between the measured balance outputs and transformed predictions from the comprehensive analysis code CAMRAD II. The modal response of the testbed is discussed and compared to a detailed finite-element model. Results reveal that the modal response of the testbed exhibits a number of characteristics that make accurate dynamic balance predictions challenging, even with the use of the balance transformation.

Descriptors :   wind tunnel tests , vibration , calibration , wind tunnel models , ROTORS , ROTARY WING AIRCRAFT , fuselages , dynamic response

Subject Categories : Helicopters

Distribution Statement : APPROVED FOR PUBLIC RELEASE