Transfer Diesel Injection Pump
Dynamic Full System Simulations
Delphi Technologies – www.delphi.com
Delphi Diesel Systems in Gillingham, Kent recently added the PumpLinx CFD software to their simulation toolset.
Delphi is a high-technology company that integrates safer, greener and more connected solutions for the automotive sector.
Delphi designs, engineers and manufactures a wide variety of components, integrated systems and modules on a worldwide basis.
Within their Powertrain division, Diesel Fuel Injection pumps are developed for a range of vehicles and operating environments. State-of-the-art CAD and CAE software is commonly used to support the design process.
Within their Core Engineering CR Pumps team, 1D Simulation methods had been used for some time with a good level of success. 3D CFD Full simulations were required to get a complete understanding of pressure signatures in the fuel pump system.
The whole fuel pump assembly needed simulating in 3D, with the majority of the fluid components in motion, in order to really understand the source of the fluid dynamics effects taking place in detail.
This included the rotating CAM, the spring, two separate dynamic valves, the bearings and in some instances a coupled sliding vane pump.
80/20 Engineering had demonstrated to the engineers at the Gillingham site, a unique CFD software, namely PumpLinx, and how its positive displacement meshing templates proved invaluable in being able to set-up such a complex fluid machinery assembly.
With this level of complexity being considered it was also extremely important that this simulation model was validated against real experimental results. Therefore, a very detailed initial study was commissioned looking at a fuel pump that was specially modified with Video Camera ports. This had a large amount of known experimental data to compare against.
A range of monitor points were added at various locations within the simulation model so that the transient flow values, pressure and velocity data could be recorded and compared to the experimental data available.
This work demonstrated the importance of knowing and assigning the correct fluid compressibility properties to the CFD model if the pressure pulsations were to be captured correctly. PumpLinx models a range of these properties as part of its advanced cavitation modelling capability.
Further work was later performed to assess the sensitivity of the pressure pulsations to the fluid properties associated with working in harsh conditions.