Ring-Force Balance System for Small Wind Tunnels

Abstract

A ring-force balance system for a supersonic wind tunnel with a small test section was developed. This force balance system can measure an applied force independently by measuring the strain on the ring part. A theoretical analysis of this system was conducted under three conditions: an infinitesimally thin ring-force balance, a ring-force balance with finite thickness, and a ring-force balance with a support arm. From the analytical results, the azimuthal location, where the strain is zero for certain force components, varied based on the balance characteristics, such as the thickness or diameter of the ring part. A ring-force balance, which is based on this analysis, was designed and fabricated. The calibrated results showed that the designed balance was able to measure the force components with high accuracy and minimal interaction.

Mach Number Effect on Supersonic Drag Reduction using Repetitive Laser Energy Depositions over a Blunt Body

“…The force exerted to the model was measured by a ringforce balance system. 31) In this paper, "drag" refers to a force acting only on the frontal surface of the model.…”