CFX Berlin-Video: CFD analysis of three-spindle screw pump

In this CFD simulation, a three-spindle screw pump with cycloidal toothing ("dreispindlige Mitteldruckpumpe mit Zykloideneingriff") has been setup with TwinMesh and ANSYS CFX. Geometry and operating conditions were taken from the dissertation "Last und Lastausgleich zykloidenverzahnter Schraubenpumpen" by Joachim Turner at Technical University Darmstadt of 2013.

The rotors have a wrap angle of 1006° with a length of 195.5 mm; axis distance between mid and side rotors is 27 mm, outer circle diameter of mid rotor 45 mm, of side rotors 27.2 mm. Radial and interlobe gap size is 0.1 mm. The fluid regions around the rotors were meshed with TwinMesh with the Outerfix approach, in this case with 360 (mid rotor) and 308 (each side rotor) elements in circumferential, 10 in radial and 1006 in axial direction, altogether 3.6 mio hexahedrons for mid rotor, 3.1 mio for each side rotor; 180 meshes for a rotational increment of 1° were pre-generated (and read at run-time by the solver). Stator mesh for simple cuboids were created with ANSYS ICEM CFD with 128,000 hexahedrons for pressure and suction side.

Simulation was done with ANSYS CFX for oil with kinematic viscosity of 68 cSt at 1,000 rpm rotational speed; suction side is at 1 bar, pressure side at 10 bar absolute. As a result, average massflow was 0.615 kg/s with variation between 0.591 and 0.629 kg/s. Average power was 969 W with main torque of 9.51 Nm on mid rotor.

The movie shows absolute pressure on rotor surfaces and horizontal cut plane (top left), rotor meshes on cross section (top right), velocity as streamlines of length 5 ms (bottom left), and animated pressure and velocity distribution (bottom right).

Find out more about TwinMesh: www.twinmesh.com

Видео CFX Berlin-Video: CFD analysis of three-spindle screw pump канала CFX Berlin