Coflow Jet CFJ-VTOL (concept design)

CFJ-VTOL (concept design)
Coflow Jet, LLC.
Coral Gables, Florida, USA
www.coflowjet.com

Founded by Dr. Gecheng Zha in Florida, USA, Coflow Jet, LLC. has developed a new airfoil technology for aircraft, wind turbines and ship airfoils that increase the efficiency of wings and airfoils. The company is also in the process of developing an electric general aviation conventional takeoff and landing (CTOL) aircraft, an electric vertical takeoff and landing (eVTOL) air taxi for advanced air mobility (AAM) and an eVTOL air cargo aircraft.

To begin to explain this new technology, conventional wings on an aircraft are shaped specifically to make the air move faster on top of the wing than on the bottom of the wing. When the air moves faster on the top of a wing, the pressure of the air decreases (or there is low pressure) while you have a higher pressure under the wing which creates the force that lifts wings into the air.

Dr. Zha has invented a mechanical system to increase the speed of the air on top of a wing. He calls this active flow control using he own invention called coflow jet (CFJ) technology. Inside the wing is a micro-compressor that blows pressurized air over the top leading edge of the wing (through duct work) and then there is duct work at the top trailing edge of the wing that collects the air and feeds it back to the micro-compressor (in duct work inside the wing) which then starts the process over again.

The CoFlow AFC airfoil utilizes powerful, energy efficient wing-embedded micro-compressor actuators to inject pressurized air over the wing surface through a suction and injection system. To create the desired circulation and momentum, a small amount of air is suctioned at the wing’s trailing edge, energized, and injected tangentially at the leading edge. Wind tunnel tests and CFD simulations have demonstrated that CoFlow’s AFC airfoil creates a super-suction effect due to extremely low leading edge pressure, achieving an unprecedented stall angle of attack of 70 degrees or more, while typical airfoils reach maximum lift in the range of 15 to 18 degrees. -Quote from Yahoo! article.

Here are some of the benefits of Coflow Jet technology:

• Increased mission efficiency
• Decreased operating costs
• Greater range
• Heavier payloads
• Better maneuverability
• Improved high-altitude performance
• Reduced drag
• Efficient anti-icing system
• Shorter takeoff and landing distance
• Faster takeoff and climb
• Slower landing speeds
• Lower noise
• Technology can be used in multiple industries

This technology is an emerging field of fluid dynamics, active flow control (AFC) in aircraft applications and is on-demand manipulation of airflow around aircraft structures. This system produces the control authority needed to enhance wing aerodynamic performance throughout the entire flight regime, including takeoff, climb, cruise, descent, landing and when maneuvering. CoFlow’s disruptive airfoil technology represents a generational breakthrough and will transform the aerodynamic capabilities of fixed wing aircraft and in other industrial applications.

CoFlow’s AFC airfoil technology was developed over a period of 15 years by Dr. Gecheng Zha, Professor and Director of Aerodynamics and CFD (Computatoinal Fluid Dynamics) Lab at the University of Miami’s Department of Mechanical and Aerospace Engineering. A NASA NIAC Fellow, ASME Fellow and AIAA Associate Fellow, Dr. Zha was recently recognized as one of the World's Top 2% of Scientists in Aerospace and Aeronautics for 2020 based on the standardized citation metrics organized by Stanford University. -Quote from Yahoo! article.

The Coflow Jet (CFJ) technology can be used on aircraft wings, airplane wings, eVTOL and hybrid-electric VTOL aircraft wings, wind turbines and used on vertical airfoils to help propel large ships. To explain how Coflow Jet (CFJ) technology helps in multiple industries, the company has three different websites listed below.

• Coflow Jet, LLC. website
• Coflow Jet Wind Turbines website
• Coflow Jet Rigid Wind Sails website

CFJ-VTOL passenger (concept design) aircraft
The CFJ-VTOL is an eVTOL four passenger concept design air taxi aircraft for advanced air mobility (AAM). The estimated cruise speed of the aircraft is 115 mph (186 km/h) and has a range of 318 miles (512 km). The empty weight of the aircraft is approximately 4,678 lb (2,122 kg). The aircraft has 10 propellers and 10 electric motors fixed on the leading edge of the tandem wings. The wings use coflow technology inside the flaps of the wings. The aircraft is powered only by batteries.

For VTOL flight, the flaps extend and move to a vertical position and the propellers provide the thrust over the flaps to use the active flow control for takeoff and landing. For forward flight, the flaps retract to a horizontal position while the active flow control continues to work to increase the range and efficiency of the aircraft.

A micro-compressor and duct work is inside the airfoil and the entire Coflow Jet (CFJ) technology assembly pushes pressurized air near the top leading edge of the airfoil and at the same time pulls air near the top trailing edge of the airfoil. It is this technology that provides the wing more lift (this is also called super-lift). This makes the aircraft more efficient on takeoffs and landings, is quieter, reduces drag, reduces fuel consumption, increases cruise speed and increases the aircraft's range. When a heating coil is added inside the wing, it will warm the air and de-ice the wing.

Dr. Zha also has disclosed that due to Coflow Jet's efficient wing technology that his air taxi concept design aircraft (or another aircraft outfitted with his active flow control technology) would work effectively on planets where the air is thin, such as Mars.

The fuselage is carbon fiber composite which is used because of its high-strength and low weight needed in all aircraft superstructures. The windows are larger than conventional aircraft allowing forward, left and right views with a solid roof above the passenger compartment. The aircraft had fixed tricycle wheeled landing gear.

There has been no timeline mentioned by the company when full scale prototypes or production aircraft are expected.

Specifications:

• Aircraft type: eVTOL passenger concept design aircraft
• Piloting: Unknown
• Capacity: 4 seats
• Cruise speed: 115 mph (186 km/h)
• Range: 318 miles (512 km)
• Empty weight: 4,678 lb (2,122 kg)
• Propellers: 10 propellers (stationary forward propellers)
• Electric motors: 10 electric motors
• Power source: Batteries
• Fuselage: Carbon fiber composite
• Windows: The windows are larger than conventional aircraft allowing forward, left and right views with a solid roof above the passenger compartment
• Wings: Tandem wings (with coflow technology inside the wings), the wing flaps turn down and uses the coflow technology to provide lift for VTOL flight, flaps return to the horizontal position for forward flight
• Landing gear: Fixed tricycle wheeled landing gear
• Safety features: Distributed Electric Propulsion (DEP), provides safety through redundancy for its passengers and/or cargo. DEP means having multiple propellers (or ducted fans) and motors on the aircraft so if one or more propellers (ducted fans) or motors fail, the other working propellers (or ducted fans) and motors can safely land the aircraft. There are also redundancies in the sub-systems of the aircraft. Can land conventionally if the VTOL systems are not working.

Related Aircraft:

• CFJ-VTOL eCargo (concept design)
• CFJ-VTOL TW (concept design)

Company Insights:

• Airframer

Resources:

• Coflow Jet, LLC. website
• Coflow Jet Wind Turbines website
• Coflow Jet Rigid Wind Sails website
• Video: DARPA Funds Research to Achieve Super-Lift, College of Engineering of Miami, Oct. 22, 2018
• Article: Xeriant Signs JV LOI with Coflow Jet to Develop Revolutionary “Green” Wing Technology, Yahoo! Life, Dec. 17, 2020
• Video: CoFlow Jet Green Aviation Presentation for Frost Science Museum, UM MechE, Feb. 25, 2021
• Article: CoFlow Jet Signs JOA with NASA for New eV/STOL Technology, Newswires, Feb. 28, 2022
• Video: Skyway - Moving the sky together, Skyway, July 19, 2022
• Video: Skyway Showcase with Coflow Jet: New Wing Technology Allows Faster, Farther, Cleaner Travel, Skyway, Feb. 1, 2023