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Why GridPro for Grundfos

 

GridPro was chosen by Grundfos for two main reasons. Superior quality of the hexahedral mesh obtained and automation capabilities to track changes in the pump geometry while maintaining the quality of the hexahedral mesh. According to Christian Brix Jacobsen, Department Manager of Fluid Mechanics Division, "Quality of the grid is of utmost importance for CFD analysis and automation is very important for saving time and obtaining faster design cycles. GridPro gives us both advantages."

Other mesh generation software cannot automatically maintain the mesh quality when the geometry is changing. The high-quality mesh is obtained by the use of proprietary optimization techniques in the GridPro grid generation engine, and automation is obtained through the use of DBC™ (Dynamic Boundary Conforming) technology in GridPro.

 

Volute optimization process

 

The challenge for Grundfos is to maintain efficiency while keeping the length of the pump short, as a compact pump is always more desirable. A design optimization procedure has been setup to achieve maximum efficiency for the given pump. The geometries have been parameterized in CATIA and are automatically pulled out of and fed to GridPro. GridPro automatically generates grids for these and sends them to CFX for fluid analysis.

The entire pump casing design process takes one hour. GridPro grids enable CFD solvers to converge faster and produce more accurate results. Faster convergence of the CFD solver leads to faster turn-around in design time. This enables Grundfos to bring products to market faster. Other grid generation software does not have the same quality and automation features for such wide range of geometries.

GridPro is a powerful and flexible grid package which can generate grids for very complex geometries. Grundfos uses GridPro as their grid generation package for a variety of geometries. These include pump casings, volutes, impellers, and other fluid passages.

The grid generation engine follows geometry changes based on a pre-built template and produces high-quality meshes for the new geometry. GridPro's DBC technology is closely linked to the topology process. It enables high quality meshes to be produced automatically. The GriPro grid generation engine uses the DBC technology with proprietary optimization capabilities to generate a high quality pure hexahedral mesh from this template. Topology is an abstraction and is related to the geometry by assignments only. For Grundfos, this means design changes in geometry can be easily tracked without sacrificing the quality of the mesh. The combination of quality and automation leads to savings in time and better pump designs for Grundfos.

 

Europump defines attainable efficiencies for pump casings. The maximum practical efficiency defined by Europump is 84.2%, while the efficiency obtained by Grundfos TP pump is 83.8%, after the pump design was optimized to obtain the highest possible efficiency.

Grundfos uses validation techniques like Laser Doppler Velocimetry, performance testing and detailed local measurements to validate the CFD results. Grundfos finds that CFD results obtained from GridPro meshes closely match test results. GridPro acts as a bridge between CATIA and CFX for Grundfos' various geometries. But GridPro also exports directly to a number of other fluid solver formats with boundary properties set by surfaces. This helps in reducing user interaction to set up CFD analysis when exporting grids.

 

GridPro enabled superior engineering solutions for Grundfos, helping Grundfos stay ahead in the competitive pump industry.

To learn more about how GridPro can enable you to stay ahead of the competition by enabling superior engineering solutions, contact us.

All images courtesy of Grundfos.