Airfish 8 gets a lift from wind tunnel experiments

For island nations, travel between cities isn’t as simple as hopping in a car. It’s important to have quick, reliable transport between islands, especially in case of emergencies.

The Airfish 8 Wing-in-Ground (WIG) vehicle utilizes the ground effect — aerodynamic changes that occur when a wing is near a surface like water or land — for improved aerodynamic efficiency.

Mingtai Chen investigated a scaled-down Airfish 8 — a passenger-carrying WIG vehicle — to better understand its unique aerodynamic characteristics.

“Compared to a common passenger transport airplane, it has a bigger weight-to-thrust ratio, which means at the same thrust, it will carry more weight,” Chen said.

However, coastal transport is still underdeveloped, since it can be difficult, or even impossible, for WIG vehicles to fly.

Chen performed a numerical simulation to calculate lift and drag on the Airfish 8 due to the ground effect. Afterward, he built a scaled-down version of the vehicle and tested it in a wind tunnel. He also used a wooden board with adjustable height beneath the model to simulate a calm ocean.

Previous papers concluded drag was reduced from the ground effect in classical finite-wing theories. But Chen’s experiments found that, for the complete Airfish 8 configuration and its conditions, total drag increased as the vehicle approached the ground, though it was smaller than the corresponding increase in lift.

Chen hopes his findings will allow for further studies on how the ground effect of the Airfish 8 will change when flying over large waves but cautions that his results are still preliminary.

“Ultimately, we are trying to come up with a strategy to overcome the operational limitation imposed on the Airfish 8 by more challenging sea conditions so that regular transport will not be interrupted by adverse weather,” Chen said.

Source: “Experimental and numerical study of a scaled airfish wing-in-ground vehicle,” by Mingtai Chen, International Journal of Fluid Engineering (2026). The article can be accessed at https://doi.org/10.1063/5.0342182 .