Modern computational fluid dynamics (CFD) software can simulate complex geometries and processes. There are two difficulties with respect to this, however. They are that multiphase systems are being considered and that they change within the millisecond. The University of Alberta has cracked this problem with the aid of Ansys CFD software. Initial results relate to the optimization potential with respect to energy use. The first patent for eccentric spiral pumps was awarded in the 1930's. Today this type of pump is broadly used especially in the petrochemicals industry. It is used for gentle supply and metering with high capability over a broad viscosity range of 0.01 to 100 Pa-sec. These pumps pump thin or highly viscous media and withstand aggressive and abrasive liquids. They also master flows that contain gas or foams with a high solids fraction. Newtonian 20 Pa-sec non-stationary isothermal flows have been studied on two different eccentric spiral pumps. The simulation has used a three-dimensional stator network made of 62,160 hexagonal elements and a rotor network made of 6,000 elements. Initial results indicate that at the same flow rate, the rotor torque and thus the energy use varies with stator design. A constant viscosity model is used for the simulations. In future work non-isothermal simulations with non-Newtonian models such as the "Power Law" and Carreau-Yasuda models will be made. These promise an improved representation of the viscosity of mixtures from crude oil, gas, and sand. This will provide information on the influence of fluid rheology on pump capabilities. Thanks to the Ansys CFD programs the manufacturer in the not too distant future will be able to optimize the stator design of the eccentric spiral pumps and make the pumps more efficient. The characteristics and advantages in use of Release Fluent 6.3 with comprehensive CFD application range are described. Diagrams.
|Translated title of the contribution||Pumps and compressors. Secret disclosed. Dynamic flow simulation of eccentric spiral pumps|
|Number of pages||2|
|Specialist publication||CIT Plus|
|State||Published - Apr 2007|