# Richard Smith's blog

## Underwater Kites Generate Electricity

There are some fascinating proposals for power generation using tethered kites and balloons, so why not investigate the equivalent of underwater kites for generating power? Why not indeed, because that is exactly what two independent teams of researchers are doing, one from Minesto, Sweden and the other from Worcester Polytechnic Institute, USA [Source: Discovery News].

## CFD Explains Santa's Whereabouts

For Santa to meet his aggressive toy delivery schedule on Xmas eve it would appear that he has to travel impossibly fast. Yet there are often sightings of Santa on his rounds, which seems to contradict this high speed hypothesis. The only way to explain Santa's whereabouts is that he uses a Reality Distortion Field (RDF). Santa's special projects division (known as Elf Works) is responsible for the RDF and it remains tight lipped on how it works. However, with the help of Computational Fluid Dynamics (CFD) we have pieced together how the RDF might work.

Iso-surfaces of velocity magnitude

## Elephant Literally Collapses into a Puddle

What happens if by suspending the laws of physics an elephant was to instantaneously transform into water? Given that approximately 70% of an elephant is already water we just need to magically convert the remaining 30% - I'll leave that as your homework assignment. Then the results would probably look something like this Volume Of Fluid (VOF free-surface) Computational Fluid Dynamics (CFD) simulation.

Elephant collapses into a puddle

## Flying Jellyfish

It seems that a day doesn't go by without the announcement of a new and innovative flying drone. Joining the throng we have researchers from New York University (NYU) who have developed a drone that flies like a jellyfish, but without the sting! Their work was showcased at the 2013 APS Division of Fluid Dynamics Meeting.

## Airplane + Helicopter + Hovercraft + Airship = ESTOLAS

What do you get if you cross an airplane with a helicopter, with a hovercraft, with an airship? The European Commission's Extremely Short Take Off and Landing on Any Surface (ESTOLAS) project.

## Inspiration from Spinning Maple Seeds

Looking to nature for inspiration (biomimicry) is nothing new. I've already covered turbine blades inspired by humpback whale fins and drag-reducing textures that mimic shark skin, so next up we have the elegant spinning maple seed.

Leading edge vortex shown by streamlines

## CFD Study Comparing Racecar Wing Mounts

A growing trend among racecar designers is to use a 'swan neck' wing mount that attaches to the pressure surface of a wing. Historically wing mounts have connected to the suction surface of a wing. What difference does the wing mount strategy make to overall car downforce and drag? Let's investigate using Computational Fluid Dynamics (CFD) on a BMW Z3 - the same model I used in a previous CFD study to show how effective adding a wing is to increase downforce.

Stream ribbons colored by velocity magnitude

## CFD Study of a Car With and Without a Wing

What difference will adding a rear wing to a car make? You can expect an increase in downforce, equivalent to a reduction in lift, and an increase in drag. To quantify these effects I simulated the aerodynamics of a BMW Z3 using Computational Fluid Dynamics (CFD) without a wing and with a wing.

Velocity contours and streamline arrows

## Failure to Simulate

Given the availability of Computer Aided Engineering (CAE) analysis tools, such as Computational Fluid Dynamics (CFD), it is a surprise that analysis tools are not used more by architects during building concept design, especially relative to the local environment around a building.

Air Velocity Vectors

## Wind Tunnel Reveals Dinosaur's Flight Secrets

Researchers at the University of Southampton have tested a model of a Microraptor (a feathered, four-winged dinosaur) in a wind tunnel and found that it was optimized for slow gliding. Its multiple wings performed the same function as a modern-day, high-lift configuration used on airliners for takeoff and landing.

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## Recent blog posts

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