Go With the CoFlow Jet

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Ge-Cheng Zha, Professor in the Mechanical and Aerospace Engineering Department of the University of Miami (Florida) explores new realms of augmenting lift on wing surfaces.  He recently presented one aspect of this study, which he calls the CoFlow Jet. Most conventional airfoils generate increasing amounts of lift with an increasing angle of attack, but that increase stops at around 12 to 15 degrees AOA.  The wing “stalls”, sometimes suddenly.  The ability to avoid this stall would increase flight safety immeasurably. Zha’s presentation at SAS 2019 at UC Berkeley, “A High Efficiency Low Noise VTOL/ESTOL Concept Using CoFlow Jet,” showed off some startling high angle of attack capabilities that went well beyond the normal limits for conventional airfoils. Phil Hendrie, a comedian with a radio and now podcast career, defined the worst possible circumstance as something that sucks and blows at the same time.  The antithesis to that is the CoFlow Jet (CFJ), offering an “active flow control airfoil.”  Described as, …

EAS VIII – A Day and a Half You’ll Never Forget

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Who would pass up a chance to stay at a nice resort, attend lectures that challenge and inspire, and meet at poolside with speakers who bring some of the sharpest minds in the world to bear on some of the biggest problems we all face?  Let’s face it.  Global warming probably won’t be going away anytime soon, and aviation seems destined to play a bigger part in polluting our otherwise near-perfect atmosphere. Unless…we learn how to make our favorite activity (in the top five for most of us, anyway), into a more responsible way to travel and recreate.  Since solving the problems which go with that responsibility will involve the best in aerodynamics, power systems and new, efficient technology, the CAFE Foundation has invited experts in these fields with demonstrated successes in meeting such challenges. To be held April 25 and 26, 2014 at the Flamingo Resort in Santa Rosa, California, the event will host speakers on everything from practical, …

Ultra High Lift Without Flaps

Dean Sigler Diesel Powerplants, Electric Powerplants, GFC, Sustainable Aviation 1 Comment

Dr. Gecheng Zha, an Associate Professor with the University of Miami has an impressive set of credentials, culminating in a Ph.D.from the University of Montreal, Ecole Polytechnique.   That, and his impressive body of work helped impress the audience at the seventh annual Electric Aircraft Symposium this last April. His work over the last decade has focused on generating high lift and low drag through circulation control on wings – even leading to the concept that wings can generate thrust instead of drag.  This integration of aerodynamic forces would lead to highly efficient aircraft capable of flying on little – or even no power. Earlier attempts to increase lift and decrease drag have relied on sometimes complex, multiply flapped and slotted wings which require powerful mechanical actuators to work their magic. Others have used rotating cylinders laid spanwise on wing leading and trailing edges, or active suction or blowing to achieve their goals.  Zha has looked at these and other …