Genova's pump
Authors: Ubaldi
Type: Numerical
Status:
Contents
Description
Flow Parameters
Reference Publications
Results
Description
The chosen test case is one among ERCOFTAC's test case ("test case U3":Centrifugal Pump with a Vaned Diffuser. It is a simplified model of centrifugated turbo machinery with a vaned diffuser. The experimental device was built by Professor Ubaldi's team of the University of Genova. This test case was described exhaustively in the report dealing with rotation. We invite you to refer to [1] for details about the geometry and vocabulary specific to the pumps. In this note, we only represent the geometry showed on Figure 1 and the pump's operating conditions in table 1.
Figure 1 - Geometric details
In table 1 Q is defined as volumic flow, Pt as the total pressure, U as the training velocity and l as the rope lenght. Indices 1,2,3 and 4 correspond to inlet and outlet of the wheel and inlet and outlet of the diffuser, respectively. The fluid temperature at the inlet stay around 298K during all th experiment, so its density can be assumed constant and equals to %$1.2kg.m^{-3}$%.
The device is equipped with pressure transducers with fast response mounted on the casing wall and a hot wire probe (3 components) in the air gap. The latter gives complete access to the velocity field on a cylindrical section located 4 mm from the wheel's training edge and 8 mm from the diffuser vanning edge (at r=0.214m). Unstationary data are reconstituted assuming temporal periodicity of physical quantities. For more details, see [1].
Table 1 - geometric data and pump characteristics
Flow Parameters
Table 2 - Data settings for simulation
At the inlet, absolute velocity is given along the rotation axis, and the formula modified to calculate the flooding velocity is the following :
%BEGINLATEX{label="bal_mom"}%
\begin{equation}
V_{d}=\frac {\phi\pi\omega R_{2}^{3}}{S_{e}} =\frac {\phi\omega R_{2}^{3}}{R_{max}^{2}-R_{min}^{2}}
\end{equation}
%ENDLATEX%
%$R_{min}$% and %$R_{max}$% are inner and outter radius of the inlet section, respectively. The inlet turbulence is calculated with the classical formulas for round section pipes with smooth walls.
The Reynolds number is about 10000 and R=0.041m is the radius at the center of the inlet pipe.
Turbulence initialisation is done through a reference length and a reference velocity according to classical formulas.
Reference Publications
[1] Combès, J.F., "Test Case U3: Centrifugal Pump with a Vaned Diffuser", ERCOFTAC Seminar and Workshop on Turbomachinery Flow Prediction VII, Aussois, jan 4-7 , 1999.
[2] Ubaldi, M., Zunino, P., Barigozzi, G. and Cattanei, A., "An Experimental Investigation of Stator Induced Unsteadiness on Centrifugal Impeller Outflow", Journal of Turbomachinery, vol.118, 41-54, 1996.
[3] Ubaldi, M., Zunino, P., Barigozzi, G. and Cattanei, A., "LDV Investigation of the Rotor-Stator Aerodynamic Interaction in a Centrifugal Turbomachine", 8th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, 1996.
Results
Simulation results available for this case:
Number of topics: 0
.
Add New Results Here.
To add results please fill in the form by clicking on the
CREATE button below. You will need to provide all the information on the form.
Please select which group or groups can access the information from the list. If you
don't want to restrict the access, please select
None.