The Future of Custom Design and Development
At Hevvy/Toyo Pumps we utilize the latest in technology to solve our customer’s problems. Whether it’s a custom impeller and volute for a specific customer application, a new impeller capable of transporting the heaviest solids in the most efficient manner, putting in time researching how wear might affect existing designs or our team developing a brand new agitator which creates the perfect combination of agitation and mixing, our Hevvy Development lab is always up for the challenge.
Today I want to focus on the competitive advantages of using Computational Fluid Dynamics (CFD) software to simulate the flow through pumps, using this technology to improve our current products or to design brand new components.
The best part of simulation is that it saves a lot of time and money in the development and prototyping phases of design. Traditionally, hydraulic theory combined with the designer’s experience would be used to generate a new design. Then a prototype would be created to physically test it. All of this can take a lot of time and be expensive, especially if results are not as good as expected, requiring this process to be repeated several times. With simulation, much of that can be performed with a few clicks followed by several hours of simulation, if that. This also makes small tweaks feasible. For example, tweaking the inlet angle of an impeller to produce the best efficiency can be a relatively quick task. Another example could involve generating a full pump curve through simulation to check the Best Efficiency Point (BEP). We have also used simulations to calculate the magnitude and direction of axial thrust of a pump to ensure the expeller vanes on an impeller are functioning effectively and ultimately make sure we use the correct bearings to handle the thrust.
CFD makes it easy to try out more groundbreaking or unconventional designs since there is virtually nothing to lose if it does not turn out favourably. This can really make the whole R&D process an open book. One major example of this was in the development of a new and improved agitator. With CFD, it was easy to try a number of completely different designs, some looking quite unusual. In the end, the design below was selected as the best since it provided the highest downward thrust to agitate settled solids beneath it while also providing mixing so solids would be picked up by the pump. Additionally it had the best wear characteristics in that it would last the longest in abrasive slurries.
This simulation technology can also be combined with mathematical optimization software to automatically search for and find the best or optimal design. Recently, there was a specific application where we needed higher efficiency in a pump due to the operating conditions. The process started out by simulating the flow through the existing pump design. That yielded baseline results and was used to compare to the physical test results to ensure the simulation was accurate. Following that, design parameters were assigned for the impeller. Parameters are simply variables that can be changed to modify the design. Some parameters included the impeller blade inlet and outlet angles and the tilt of the blade. These parameters were all plugged into the optimization software and it then began randomly modifying the parameters to generate different designs, then simulating and finally obtaining an efficiency result for each design. The optimization software can then hone in on designs that look promising and narrow down to the optimal design.
CFD also opens up more possibilities as it allows us to really look inside our pumps and see what is going on when they are running. There are endless options to calculate and view the results of a simulation. Of course, important results such as head, efficiency and power are calculated from a simulation. Axial and radial thrust can also be measured as discussed before. Visually, pressures and velocities are commonly examined to look for high or low pressure zones or to find areas of recirculation. Forces through the pump can also be investigated to look for areas where there may be excessive force on a surface.
CFD software has really opened up a lot of doors for Hevvy Pumps and helped change the design phase. More time can be spent in design than in prototyping and testing. We now have a lot more freedom to investigate potential designs that may have been previously considered "not worth it" for the time and money it would cost. We can run simulations on new components before ever going to production. It has also proven invaluable to investigate our current products to see what is really going on and determine areas for improvement by making modifications or even completely redesigning components.
If you or your customer has a custom pump design challenge you want us to look at, give us a call. We’ve designed to order before and we’re happy to do it again. Anything to meet the growing challenges of our customers.
A Guy Who Knows Some Stuff