Harnesses Pressure Differentials to Separate Water from the Air, Generating a Moisture-Free and Cooling Airflow
This serpentine-shaped component separates water from atmospheric air in uncrewed aerial vehicles (UAVs) to provide pure air to the interior electronic components and cool them during operation. While separating water from air is challenging, it has many uses and applications, including producing drying air.
UAVs possess a range of military and civilian applications, such as conducting search and rescue operations, fighting wildfires, and surveying land. These applications require UAVs to withstand the elements, including protecting their electronic components from rainwater. The electronic components generate immense heat and can destroy a UAV if not dissipated. A simplistic solution to these two problems is to use waterproof electronics and place them outside the skin of the UAV, where cooling airflow can reach in the form of the air streaming past during flight. However, an unavoidable drawback of this solution is that waterproofed electronics carry a sizeable cost premium. Placing the electronics inside the UAV instead shields them from some water. Still, it does not eliminate the necessity of waterproofed electronics when factoring in the requirement for bringing in external air to cool the electronics. When it rains, this air intake contains enough moisture to damage the electronics.
Researchers at the University of Florida have developed a UAV air intake device that generates a cooling stream of air while removing the water, enabling UAV designs with more cost-effective electronic components sheltered internally but sufficiently cooled. This device separates moisture from the air without moving parts or electronics and integrates with commonplace UAV designs to cool the electronics without waterproofing them.
Application
Intake airflow to cool the electronic components of UAVs without exposing them to water
Advantages
- Separates the vast majority of water from the airflow that cools the control electronics, generating significant cost savings by enabling the use of non-waterproofed electronics
- Eliminates the need for heat sinks in the UAV’s fuselage, enhancing its structural integrity
Technology
The air flowing past a flying drone composes molecules, such as gaseous nitrogen and oxygen, and contains water droplets. The water droplets and the gaseous molecules move in response to pressure differentials from high-pressure to low-pressure regions. However, the mass of the water droplets is many times larger than that of the gaseous molecules, so the former responds to pressure differentials much more slowly. This means that water droplets will navigate a highly curved “S” tube with great difficulty and will often become trapped in its bends.
When the curved tube is put inside a UAV wing, it can access the various pressure regions outside the wing to dictate the flow of the water droplets and gaseous molecules. Specifically, placing the intake valve at the highest-pressure surface of the wing induces both types of particles to flow toward the interior region of the UAV housing the electronics. As mentioned, the water is trapped in the bends during this flow. Connecting one or more of these bends to outlet valves at low-pressure surfaces along the wing causes a local outflow of whatever is in the bends towards the low-pressure region. Since the water droplets disproportionally land in the bends, these outlet valves remove much of the water from the air flowing in the tube, delivering a non-damaging yet cooling air stream to the electronics inside the UAV.
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