Flomerics and Matchstick Productions have released a short video, which for the first time reveals the complex 3D airflow around a wingsuit that enables human beings to glide through the air like a bird.
The video (available at http://www.youtube.com/watch?v=Q09fO5SqHIo) combines actual footage of human flight in wingsuits with airflow simulations using CFD (computational fluid dynamics) software. The wingsuit flight segments come from the film ‘Seven Sunny Days’ by Matchstick Productions.
Flomerics’ EFD family of CFD software was used to calculate the fluid flows and pressures that produce lift and drag forces which enable wingsuit fliers to glide with extraordinary control – even tracking the contours of rock ledges and other obstacles from just a few feet.
The wingsuit flier enters a freefall wearing both a wingsuit and a parachute. When jumping from a base jump site or a helicopter, the flier begins with a vertical drop to use the forces of gravity to accelerate to a speed that the wingsuit can then use to produce lift.
Wingsuit fliers typically fly at speeds of about 60mph. Fliers manipulate the shape of their bodies to balance the aerodynamic forces and create the desired amount of lift and drag. The hands act as ailerons and very small hand movements control pitch and roll movements.
An experienced flier can demonstrate amazing manoeuvrability by arching or bending at shoulders, hips and knees, or changing the shape of the torso. The wingsuit flier finally lands by deploying a parachute.
Flomerics’ software made it possible to represent the human body in 3D, and engineers added thin shell elements between the arms and torso and between the legs to create a model of a human wearing a wingsuit.
The rotation of key body joints such as wrists, knees, elbows was specified and changed within the solid model. Then they attached boundary conditions to the model, such as giving the body a forward velocity of 60mph.
All ancillary data required for flow simulation, such as material properties, were associatively linked to the CAD model and carried along with all design changes. Then the mesher created the mesh.
Flowmerics says that while many engineers still think of CFD as difficult, time-consuming and expensive to use, this application demonstrates that latest generation software is anything but.
“EFD’s ability to integrate CFD into the design process allows design engineers to focus on the physics of the problem, which, in most cases, they already understand well, and generate results much more quickly,” says a company spokesperson.