Optimizing components that must fit into tight spaces can be a daunting task, even for the most experienced designer. Consider the HVAC system of a car, which supplies air to the vehicle’s cabin. Today, air conditioning is deemed standard equipment even in entry-level automobiles, so manufacturers must build it in. Its critical components – manifold ductwork — are located under the hood amid the well-planned jumble of engine, radiator, battery, transmission, and auxiliary structures. Not much room in there … and that’s just one of the complications. Continue reading
Because fossil fuel resources around the globe are finite, an overriding engineering design challenge is energy efficiency and sustainability. Today I’ll use tunnel ventilation fans as an example to illustrate how CFD simulation and advancements in our Adjoint Solver in ANSYS 18 can optimize fan blades performance.
According to a report by Mosen Ltd., a leader in this industry, the “greening” of tunnel ventilation is still in its infancy. The application consumes substantial power, sometimes several megawatts; in addition, governmental regulations often require tunnels beyond a certain length (for example, 300 meters) to have ventilation systems that disperse exhaust and control smoke in case of fire. As a result, tunnels need more ventilation capacity than what would be needed for day-to-day air quality. Continue reading
In a previous blog, I shared with you my excitement about the power of the adjoint solver technology for shape optimization from ANSYS. Since then I have been working tirelessly to make this remarkable technology even more capable. CFD engineers can now understand their designs better and can perform smart shape optimization, all for larger problems with richer physics thanks to the adjoint solver technology.
My numerous interactions with people from all around the world confirmed what I knew: the adjoint solver technology is powerful and has the capability to enable a sea-change in the fluid design process. The technology is already having a positive disruptive impact on design, especially among the early adopters. Products are being improved. Established concepts about some types of fluid systems and how they function have been overturned. New manufacturing procedures are being attempted in order to produce the shapes indicated by the adjoint.
When I first encountered adjoint methods as a post-doctoral researcher at NASA, I could see that there was enormous potential in this approach. It was only after joining Fluent, and subsequently ANSYS, that the time was right to develop an adjoint solver for anyone using simulation, not just for those using in-house codes. Given that there were many, many users of ANSYS computational fluid dynamics simulation tools, there was a clear opportunity to deploy this technology globally and impact the design process positively for a lot of organizations. This compelled our adjoint solver project team to overcome some of the significant technical challenges in developing this technology. It was a tough road, but the results have made it all worthwhile.
The adjoint solver calculates sensitivity information for a fluid system. The flow problem is solved in the usual manner. Then the user selects some measure of performance of the system as being of particular interest. The drag or downforce on a car and pressure drop in an internal flow system are common examples. The adjoint solver is run in a manner quite similar to the flow solver. A wide variety of sensitivity data is generated, including the sensitivity of the result of interest to the geometric shape of the system. For many people this type of result needs to be seen to be believed, at which point disbelief turns to delight. Continue reading