Design and Numerical Verification of an Electric Ducted-Fan Propulsion Experimental Platform with Two Configurations

The future of quiet, clean flight often looks like a fan hidden inside a tube. This is the electric ducted fan, a propulsion system where a powerful motor spins blades inside a carefully shaped cylinder. Unlike a standard airplane propeller that sits out in the open air, this design uses the tube to guide the air, squeezing it and speeding it up to generate thrust. Engineers are drawn to these systems because they can be tucked into wings or fuselages, offering a flexible way to power the next generation of electric aircraft. However, building a machine that works well on a drawing board is very different from building one that works in the real world. To know if a fan and its tube are truly efficient, scientists must measure how much energy the air loses as it rushes through the system. If the tube is shaped poorly, the air swirls and stalls, wasting power. If it is shaped well, the air flows smoothly, preserving its energy to push the aircraft forward.

To solve this problem, a team of researchers at Shanghai Jiao Tong University and the China Aerospace Science and Technology Corporation designed a new, large-scale testing ground. They built a specialized experimental platform capable of holding two different types of fan setups: one where the fan is mounted directly onto a section of an airplane wing, and another where the fan sits inside a standalone tube. The goal was to create a reliable environment where they could test how air behaves inside these systems without the interference of wind or ground effects that usually mess up measurements. Because building and testing physical prototypes is expensive and time-consuming, the team first used powerful computer simulations to verify that their new test bench would work correctly. They modeled the flow of air through the test chamber, checking to see if the air would remain steady and uniform before it even reached the fan.

The researchers found that their new platform was up to the task. When they simulated air moving through the test chamber at speeds ranging from a gentle breeze to a powerful 100 kilograms per second, the airflow remained smooth and stable. This stability is crucial because any turbulence coming from the test room itself would distort the results, making it impossible to tell if a fan was performing well or poorly. The simulations showed that the air entering the fan was clean and consistent, regardless of whether the fan was attached to a wing model or standing alone in a tube. This confirmed that the physical test bench they designed would provide accurate data for future experiments.

Once the platform was validated, the team turned their attention to the performance of the two fan configurations. They measured a specific metric called the total pressure recovery coefficient, which essentially tells engineers how much of the air's energy is preserved as it travels through the system. A higher number means less energy is wasted. The results were impressive. For the fan mounted on the wing, the system preserved more than 99 percent of the air's energy. For the standalone tube model, the efficiency was even slightly higher, preserving over 99 percent of the energy as well. These numbers indicate that both designs allow air to flow through with very little loss, a sign of a well-engineered propulsion system.

The team did not stop at simply confirming the designs worked; they also looked for ways to make them better. They realized that the shape of the tube's entrance, where the air first enters, played a significant role in how smoothly the air moved. By changing the entrance from a flared shape to a more streamlined, curved lip, they were able to guide the air more gently into the fan. This small geometric change had a measurable impact. In their simulations, the optimized tube entrance reduced the energy loss even further, pushing the efficiency rating up to nearly 99.3 percent. This improvement proves that even subtle changes in the shape of the intake can significantly boost performance.

The study also addressed a practical question for anyone building a test facility: where should the fan be placed inside the room? The researchers simulated the fan at the front, middle, and rear of their test chamber. They found that the position did not matter. As long as the air was flowing smoothly into the room, the fan performed the same way regardless of where it sat. This finding gives engineers great flexibility when designing their own testing spaces, as they do not need to worry about precise placement to get valid results.

Ultimately, this work provides a solid foundation for the development of electric aircraft propulsion. By designing a robust test platform and verifying its performance through detailed computer modeling, the researchers have created a tool that can reliably measure how well electric ducted fans work. Their findings confirm that these systems can achieve high efficiency and that careful attention to the shape of the air intake can squeeze out even more performance. As the aviation industry moves toward greener technologies, having a reliable way to test and refine these powerful fans will be essential for turning the promise of electric flight into reality.