Reynolds-number dependency of boundary-layer transition location on stratospheric airship model

A study was conducted to investigate Reynolds-number dependency of boundary-layer transition location on stratospheric airship model. The experimental model was based on the prototype of the HiSentinel Airship 50. The 54-m-long HiSentinel50 was designed to fly at an altitude of 20 km with cruise speed of 37 km per hour, and the volumetric Reynolds number in cruise was of specific dimensions. A six-component strain balance was used to measure the drag of the small model in the D1 wind tunnel. The scale for the drag component of this balance is 1 kg, with an accuracy of 0.28% at full scale.