Submitted by Richard Smith on October 17, 2012 - 13:01
I think everyone is well aware of the link between tsunamis and earthquakes after the devastation wreaked in recent years on Japan and Indonesia. However, there is a lesser known water wave called a seiche that is limited to semi-enclosed and fully-enclosed bodies of water, such as lakes, bays, swimming pools, and even puddles. I went searching for links between earthquakes and fluid dynamics after I experienced a minor earthquake (4.0 magnitude) here in New England.
Submitted by Richard Smith on September 24, 2012 - 18:52
What if you could change the shape of a tensile structure according to the natural loads, such as wind forces, it experiences? In exploring this question researchers at the University of Stuttgart and the company Bosch Rexroth came up with a tensile canopy (membrane) - nothing new there. However, their novel design uses a feedback system driven by a sensor array connected to hydraulic rams that apply counter forces to natural loads.
Morphing Tensile CanopyImage courtesy of Bosch Rexroth
Submitted by Richard Smith on August 30, 2012 - 12:50
If you are a ketchup manufacturer then maintaining your ketchup at the right consistency is a primary concern - same goes for ketchup connoisseurs. A new procedure developed by Bandulasena, et al at the University of Sheffield combines a simple experimental observation and Computational Fluid Dynamics (CFD) to characterize the viscosity of a non-Newtonian fluid, such as ketchup, so we can be confident that our ketchup will flow.
Caedium Free Surface CFD Simulation for a Non-Newtonian Fluid
Submitted by Richard Smith on August 15, 2012 - 11:30
Can't get enough of Caedium's free surface simulations? Then this new post is for you. This animation shows a transient CFD simulation of a dam break over an obstacle. The simulation is performed in pseudo 2D, i.e., it is one cell thick.
Submitted by Richard Smith on August 7, 2012 - 11:31
This animation, created by Caedium Professional, shows a transient multiphase CFD simulation of water filling a tank that is initially filled with air. The free surface is shown as blue for the air-side surface and red for the water-side surface. Each frame of the animation was automatically rendered by POV-Ray (a ray-tracer) through Caedium.
Submitted by Richard Smith on July 16, 2012 - 12:41
Exercise is a crucial ingredient for astronauts to maintain some semblance of their physiological well being and if you can combine that with exposure to artificial gravity then all the better. Enter the Human Powered Centrifuge (HPC), possibly destined for the International Space Station (ISS). It's an un-stationary bicycle that when pedaled spins around generating artificial gravity. Problem solved, right? Not so fast - nothing in space is that easy. When exercising, astronauts generate up to two times more carbon dioxide (CO2) than when relaxing and that level of CO2 could potentially cause problems for the sensitive ISS life support system. What to do? CFD to the rescue.
Submitted by Richard Smith on July 3, 2012 - 13:16
Say you've been tasked with designing a new water pleasure craft optimized for speed called the Slickjet (fictional name). You ask the fundamental question - how do you travel fast through water? Easy, get as much of your Slickjet out of the water as you can. You know that the drag force acting on a totally submerged shape in water will be about 1000 times higher than for the same shape in air - the drag force scales according to the density of the fluid and water is 1000 times denser than air. Of course this assumes you are willing to get FAA approval for an aircraft rather than a boat. However, there is an alternative in that if you can somehow cocoon parts of your Slickjet in an air bubble as it moves through the water then you can convince the physics that those parts of your Slickjet are moving through air rather than water. This process is known as super cavitation and results in the drag forces acting on those parts of your Slickjet being more like those encountered in air rather than water.
Submitted by Richard Smith on June 7, 2012 - 13:33
Cycling is one of the fastest sports in the Olympics. With that speed comes an increased importance on aerodynamics. In cycling the aerodynamic design is focused on minimizing drag. However, as with swimming, there are carefully crafted rules that ensure there is only a narrow scope for aerodynamic optimization to gain a competitive advantage.