Development of a Customizable Multi-Axis Load Cell for Wind Tunnel Testing

Wind tunnel tests provide controlled and repeatable flow fields that enable the study of flow characteristics around physical objects. They provide invaluable insights that are crucial in validating designs and computational models. Due to their broad application, wind tunnel facilities are driven to accommodate diverse test articles and measurement requirements, necessitating adaptable setups and instrumentation. Multi-axis load cells are widely used to measure force and moment components, but commercial systems, while precise and reliable, are inherently inalterable, limiting their use cases to tests that have matching force ranges. This paper describes the development of a modular multi-axis load cell designed for adaptability across a wide range of wind tunnel test requirements. Composed of six single axis bar load cells, the modular multi-axis load cell is configured to capture all six degrees of freedom. The load range of each axis can be altered by swapping out the single-axis load cells with different capacities. The electronics responsible for amplifying and capturing the signals from the load cells are separate from the load cells, enabling quick reconfigurations. The main sensor structure is made from aluminum extrusions that make the system easy to incorporate into existing structures.This multi-axis load cell will be validated using a spinning cylinder setup used for studying the magnus effect and a finite wing setup with variable angles of attack. In each case, the test data will be compared against commercial systems and theoretical results for accuracy. Standard performance metrics such as uncertainty, repeatability, drift, and hysteresis, will be used to compare the performance of the multi-axis load cell against commercial sensors.