Victor Maldonado’s lab at Texas Tech is on the cutting edge of developing new technology for the city commuter flight industry.
Flying cars?
Well, not exactly, but Texas Tech University researcher Victor Maldonado, an associate professor in the Edward E. Whitacre Jr. College of Engineering's Department of Mechanical Engineering, is on the cutting edge of helping develop technology for urban air mobility (UAM) vehicles, and ride-sharing flights across cities may not be as far off as you think.
With support from NASA, Maldonado is leading a team of students in the University Student Research Challenge. Through the program, eight undergraduate and graduate students from his lab are working to develop new technologies that address the two biggest technical concerns with UAM vehicles: Noise and flight efficiency.
“The main hurdle for these vehicles is noise,” Maldonado said. “That's the main technical push is to make these vehicles quiet enough so that they don't disturb the public. We're developing ways to reduce the noise by shaping ducted rotor blades which are inspired by the maple seed. That's No. 1.
“No. 2 is to get them to be more efficient, economically and aerodynamically speaking, because they use batteries and electric motors. With current battery technology, these vehicles won't be able to fly farther than around 150 miles before the battery runs out and they have to land.”
The idea is to develop a fixed-wing aircraft (think airplane) capable of vertical takeoff (think helicopter) and quiet enough to pick up passengers in a neighborhood park without waking up the neighbors.
Some of the technology exists already. Vertical-lift vehicles have been built using batteries to power fans attached to the wings, but the number and location of fans have proven to be stumbling blocks for developers.
Multiple exposed fans and large ducting systems create drag, which inherently creates more noise as the air struggles to pass over the wings and through the fans.
The novel ducted fan-wing concept from Maldonado's team takes a new approach, moving fans and altering the ducting.
“We've created a new airfoil that partially hides the fan underneath the wing, so when you look at the wing from the front, the exposed fan is about 50% hidden from the freestream,” Maldonado explained. “Our hypothesis is that by hiding these fans, you can greatly reduce the form drag of the aircraft. The thicker the body of the aircraft is, the more drag it'll have because it has to push against a much greater mass of airflow. By decreasing the exposed fans, we can get less form drag on the wing as well as reduce the interference drag between the fans and the wing.
“Most turbofans, as you'll see when you go to the airport, the entire turbine is exposed to the freestream. You have this large fan in front of the wing and it has to propel itself and the entire aircraft against the wind. You can see when you look at our design that the ducted fan is much more hidden.”
Along with hiding the fans, the design from Maldonado's team also offers a new take how the fans are used for vertical lift and forward propulsion.
“Traditionally you have a big intake in the front of fixed wings for flight, and then in the back is where you have your ducting,” Maldonado said. “The bottom surface of our new airfoil recreates some of the flow conditioning of an inlet without using a duct, allowing us to reduce the size of the actual duct around the fan.
“These fans are mounted to multiple flaps on the wing and these flaps will simply rotate – similar to a current flap on an aircraft – although ours rotate by 90 degrees so we can vector the thrust to achieve vertical takeoff and transition to forward flight.”
For those now dreaming of taxi flights across the Dallas-Fort Worth Metroplex to avoid traffic on I-30, urban air mobility vehicles haven't gotten that far just yet.
There are still plenty of hurdles to overcome. Maldonado says that vertiports – landing spots for vertical takeoff and landing aircraft – could fit on top of skyscrapers or in small parks, but how exactly they will work within regulations is still a bit of an unknown.
But, he says, you might not have to wait as long as you would think.
Two companies in California, Joby Aviation and Archer Aviation, are already doing test flights and working toward safety certification with the Federal Aviation Administration.
“There will be some restrictions and failsafe functions on these electric vehicles of the skies before they are allowed to transport passengers,” Maldonado said.
“But I would think that within a few years, say by 2025, we will have the ability to ferry passengers in some of these big cities.”
