Infrared Thermography and DIT of Quadcopter Rotor Blades Using Laser Heating

Abstract

A measuring method to detect wall flow topologies by active infrared thermography was developed. Quadcopter rotor blades were studied in typical hover and forward flight conditions, while using a high-power infrared laser to heat the blade surface. By this, the distance between heat source and measuring object could be significantly increased compared to conventional heat sources. The resulting images show little blurring at high signal-to-noise ratios. In steady-state flow conditions, wall flow topologies could be detected reliably and show good agreement with performed oil-film interferometry measurements. Wind tunnel experiments at forward flight conditions were conducted and indicate unsteady shifts of the transition location.

Keywords

• thermography
• boundary-layer transition
• rotor blades
• oil-film interferometry
• laser heating
• differential infrared thermography