With the advances in modern technology, Computational Fluid Dynamics is becoming increasingly popular. However, you may be wondering why Computational Fluid Dynamics is often the preferred method of modeling. You may be wondering what CFD provides that other methods of modeling cannot. While both physical model tests and CFD simulations have their own multitude of pros and cons, in my experience, it has become clear that CFD is not only usually cheaper and faster than other methods, but oftentimes, safer CFD allows for endless alterations in variables and provides the security that physical model tests cannot always provide. When working with dangerous gases, harmful fluids, or unsafe environments, CFD provides for a safer alternative.
The following segment from Computational Fluid Dynamic,’ written by Victor Udoewa and Vinod Kumar, discusses specific examples incorporating CFD, explaining and proving how CFD simulations can be more useful than physical model tests in particular situations.
Most often, CFD is used when a computational solution is faster, cheaper, or more convenient. Convenience may be due to time or safety or another reason. If we wanted to create a database of information about 3D flow around a cylinder for different types of fluids at varying speeds, CFD is quite helpful. It would take quite a long time to change the fluid in our flow container and clean the container for every type of fluid we desired. It would also take some time to change the speed of the flow. In this case, it’s much faster to simulate it computationally. Then, anytime we wanted to change the speed of the flow, we simply would change one number in a computer input file. Or if we wanted to change viscosity and density for the fluid (representing a different fluid) we would just change the corresponding values in a computer input file. In this case, CFD is faster. Now imagine if you were doing space defense work for a government, and you were asked to do fluid dynamics simulation of the combustion dynamics during an explosion or when a space shuttle launched.
(1). It would take immeasurable amounts of money to do test launches over and over as you studied the combustion dynamics of space shuttle thruster ignition. And it would take large amounts of money to test explosive devices, especially considering the damage they cause. In these cases, CFD is, again, quite helpful. The only costs in CFD are the time of creating a computer model, choosing the right mathematical model, coding it, and the power and computer time required to solve the equations. But it is plain to see that CFD is cheaper. What if you were hired to help design material for the outfits of swimming athletes? Your company gave you the job of studying sharks and their agile ability to swim and maneuver through the water. So you start by trying to study the fluid dynamics around the shark skin.
(2). How convenient is it to locate sharks and place them in some type of testing container where you have probes and measuring devices located? How convenient is it to place probes on the body of the shark itself? How safe is it to work with the sharks in that manner? No, it’s better to create a computer model of a shark and get the information for the shape, design, feel, and density of its skin and to use this information to run simulations. It is clear that CFD is more convenient in this situation. Sometimes a CFD simulation can be all three—safer, cheaper, and more convenient. Imagine a situation in which two paratroopers, jumping from both side doors of a military cargo aircraft, always crash into each other down below.
(3). In order to analyze the fluid dynamics of the problem to see what air flow forces are affecting the paratrooper paths, you would need to perform test jumps with paratroopers. However, that is potentially injurious and not safe. You would also have to rent the plane, pay for the rental by hour, hire the test pilot, and pay for all the equipment for the jump. That is expensive. Lastly, the organization of the use of the military aircraft and personnel and equipment takes many months, and it can take from 6 to 12 months to plan the test. https://cdn.intechopen.com/pdfs/31925/InTech-Computational_fluid_dynamics.pdf
From the previous examples, some major advantages of CFD simulations should become clear. When dealing with fluid dynamics within your company, it is in your benefit to choose an option that is less expensive, fast, and safe. If your company is looking to outsource CFD, please give me a call. I’d be more than happy to discuss a variety of options and how I can help you with your upcoming project.