Archer has completed another round of wind tunnel testing at the RUAG Large Subsonic Wind Tunnel in Emmen, Switzerland. The six-week campaign collected data to validate Midnight’s aerodynamic models, load predictions, performance, stability/control characteristics.

The data will be used to validate against full-scale results in Archer’s upcoming flight test program of its ‘Midnight’ eVTOL. DeHarde, a German based model creator, built a 27.6% scale of Midnight for the wind tunnel testing.

The purpose of this test campaign was to develop a comprehensive dataset to validate Archer’s engineering design tools and to confirm the aerodynamic predictions of the Midnight eVTOL. Overall, 878 measurement sweeps were made by varying model angle of attack and sideslip and capturing force and moment trends for over 400 different model configurations. These model changes included varying control surface deflections, adjusting forward boom tilt angles, and stepping through an airframe component build-up. This build-up started with a bare wing/fuselage and then successively added booms, landing gear, tail, and stopped lifter propellers. This build-up approach allowed Archer to investigate and clearly understand the incremental effects of each airframe component.

The results further reinforce confidence in the capability and performance of the Midnight design. For example, cruise drag predictions trend extremely well with test data, which in turn further validates the confidence in Midnight’s range. The measured stability characteristics reinforce that the V-tail, flaperons and ruddervators are correctly sized and that they have adequate aerodynamic control power, while also confirming that control surface hinge moments meet requirements and that our actuators are properly sized. Testing for simulated ice accretion has given the team a good understanding of the speed additives necessary to protect the aircraft from performance degradations that we would expect to see during an inadvertent icing encounter.

The company has also completed series of wind tunnel testing at Politecnico di Milan, University of Florida, and University of Notre Dame.

Why it matters: Wind tunnel testing represents a significant risk-reduction and validation milestone for Archer. With the tests, Archer can nearly replicate real-life flight conditions and validate various components in the design/configuration of Midnight. This data will tremendously in finalizing the flight test configuration and contribute to the timely entry to service of Archer’s Midnight eVTOL.

Source // Archer Aviation


Posted by Ross Piscoran