A bird bursting from the ocean or a mobula ray launching skyward makes the transition from water to air look effortless. For unmanned aerial vehicles (UAVs), commonly known as drones, it’s one of the hardest maneuvers to replicate.
Now, UCF researchers are studying how wing shape and motion affect that split-second transition — work that could help improve future amphibious UAVs.
Associate Professor of Aerospace Engineering Samik Bhattacharya and aerospace engineering master’s student Dominic Polidoro ’25 are investigating the physical forces that interact as a wing exits the water and enters the air, a process known as egress. Supported by a grant from the U.S. Army Combat Capabilities Development Command, known as DEVCOM Army Research Office, the nine-month project aims to develop mathematical models to improve the technology used in military amphibious vehicles.
The research could also expand the use of amphibious UAVs in civilian scenarios such as search-and-rescue missions in coastal areas, ocean monitoring and disaster response.
“This technology can … enable seamless air-water operations without the need for separate vehicles,” Bhattacharya says. “In 10 years, amphibious UAVs could perform reliable and stable dives and exits with better payload capacity and autonomous control in complex environments, far beyond today’s unreliable transitions.”
While researchers have extensively studied how drones enter water, far less is understood about how they exit it. Previous studies show that as a wing rises from the water, the lift generated by it will increase until it suddenly reverses direction before stabilizing. Why this occurs is not yet known, but the answer is crucial to understanding UAV performance.
“In general, when a UAV egresses, it causes lift overshoot followed by a sharp drop,” Bhattacharya says. “Such rapid changes in lift forces can create instability, leading to loss of control. Understanding this transition will not only improve our knowledge of creatures in nature but also allow for drone designs that can use or mitigate the lift increase and decrease that occurs.”
Inside the Experimental Fluid Mechanics Lab in UCF’s Department of Mechanical and Aerospace Engineering, Bhattacharya and Polidoro use a water tank and 3D-printed wings to study how surface deformation, waves and vortex shedding interact during egress. They aim to better understand the physical forces that drive this transition.
“It’s difficult to disentangle the effects of surface deformation, waves and vortex shedding because they occur simultaneously on very short timescales and strongly influence each other,” Bhattacharya says.
The duo presented earlier findings from their research at the 2026 American Institute of Aeronautics and Astronautics SciTech Forum in January.
Faculty Background
Bhattacharya joined UCF in 2016. He earned his doctoral degree in aerospace engineering from The Ohio State University, his master’s degree in aerospace engineering from Auburn University and his bachelor’s degree in mechanical engineering from the National Institute of Technology Warangal, located in India.