Functionality / features: HSVA’spropeller panel program ppb is offered on a license base for the use by our customers. The program is designed to predict the performance of the propeller behind the ship and to resolve, how the working propeller is registered by the hull. As a side effect of establishing a Panel Method for the propeller one obtains a natural byproduct, namely a panel method for the hull working on the same basis. This helps to assess the pressure fluctuation problem rigorously as the behavior of the pressure field emitted by the cavitating propeller is analyzed in the presence of all essential boundaries.
In general the method is able to take into account any detail of the blade geometry, since it is a surface panel based approach. It is also capable to include pods and ducts. Since propeller section details considered for the leading edge or at the tip are becoming a matter of interest, the panel method approach may help to trace the flow-effect related to changes in that area.
One incentive of ppb is the strict triangulation of trailing edge panels and the surface quality dependent triangulation of panels in other blade areas (see Fig. 1).
The special features of the method may be summarized as follows:
- A mixture of quads and triangles guarantees an optimum surface panelling.
- Transient flows are solved in the frequency domain.
- Cavitation is predicted 3D unsteady.
- Any hub or hub-extension is possible.
- The propeller hull pressures module accounts for hull and free surface influence.
Software + Licensing: To cover the fully wetted propeller flow, the effect of cavitation on the blade surface and the influence of the hull, the method is divided into 2 modules:
- The program ppb (Propeller Potential Based) solves the unsteady fully wetted propeller flow and calculates the sheet cavitation on the blades. The results describing the cavitation extent and volume are added to the singularity system from the fully wetted solution.
- The program sbfs (Solid Boundary Free Surface) determines, how the hull and the free surface effect the propeller pressure field.
We supply this program system on an unlimited license base. As can be read from Fig. 2, the usage of the program system is supported by a Graphical User Interface (GUI), which helps to manage the process of geometry import and surface panel system generation.
A manual describes the propeller/hull panel program system.
Figure 1: Panel system for a 5-bladed propeller before and after triangulation
Figure 2: Graphical User Interface related to the Panel Method ppb