ABSTRACT
This chapter provides a brief classification of techniques aimed at quantification of forces and moments on fixed or rotating wing systems. It focuses on micro-force measurements in conditions of quiescent flow, especially aimed at characterization of flow control actuators. The forces and moments acting on an aerodynamic body under the influence of external or internal flows can be steady or unsteady and are a function of a wide variety of conditions. Typical wind tunnel measurements of forces and moments can involve complex geometries, orientations, and degrees of freedom (DOFs). The chapter explains the measurement of aerodynamic loads in the environment of wind tunnels. Steady measurements are by far the most common and straightforward way of using force balances. Cantilever balances have been one of the oldest implementations of wind tunnel balances and are still in use today. One of the most popular types of balances is based on the application of strain gauges.
