Wind tunnel balance

US4845993A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Warren L. Horne · Tullahoma, US
• Nans Kunz · Fremont, US
• Phillip Luna · San Jose, US
• Andrew C. Roberts · Milpitas, US
• Kenneth Smith · Porum, US
• Ronald C. Smith · Long Beach, US

Key dates

• Filing date: May 18, 1988
• Grant date: Jul 11, 1989
• Expiry date: May 18, 2008

Classification

• Technology area (CPC G): Physics
• CPC primary: G01M9/062
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A flow-through balance is provided which includes a non-metric portion and a metric portion which form a fluid-conducting passage in fluid communication with an internal bore in the sting. The non-metric and metric portions of the balance are integrally connected together by a plurality of flexure beams such that the non-metric portion, the metric portion and the flexure beams form a one-piece construction which eliminates mechanical hysteresis between the non-metric and the metric portion. The system includes structure for preventing the effects of temperature, pressure and pressurized fluid from producing asymmetric loads on the flexure beams. A temperature sensor and a pressure sensor are located within the fluid-conducting passage of the balance. The system includes a longitudinal bellows member connected at two ends to one of (1) the non-metric portion and (2) the metric portion and at an intermediate portion thereof to the other of (1) and (2). A plurality of strain gages are mounted on the flexure beams to measure strain forces on the flexure beams. The flexure beams are disposed so as to enable symmetric forces on the flexure beams to cancel out so that only asymmetric forc…