The progress of the calculation of the propeller, since the beginning of its history, includes different methods that have been merged and combined to give the method elements of modern blades:BEM(Blade.Elements.Momentum).The method of calculating propeller blade elements by combining the theory of Froude, and the vortex theory, allows the calculation of axial and tangential induced velocities based on performance (cd et cL according to Reynolds) of the profiles.This method can incorporate the effects for blade tip losses (proposed by Prandtl) and fixes for highly loaded propellers (proposed by Glauert). Considering that the duct of a propeller eliminate losses at the blade tip, It is possible to model a ducted propeller, considering the performance with or without loss of blade tip:
These methods propeller calculation are given on page: theoretical concepts relevant to the design of propellers and wings.
Once the induced velocities are known for each element, the geometry of the blade can be built and overall performance of the propeller can be evaluated.
Details of the induced velocities and forces calculated for a blade element in héliciel
When it is desired to give a precise form to our propeller to control resistance, its shaft power, its thrust, performance or its operating point,it is necessary be able to select and apply the profile shape along the blade. Héliciel automates the selection, and research performance profiles, with its interactive database. This specificity allows Heliciel produce the 3D model optimized in terms of twisting,ready to be used in Cad (igs 3d files of blades), while giving the performance of power, torque, thrust... This provides a significant time savings in the study of a propeller.
The database hydrodynamic aerodynamic profiles, integrated with héliciel, automatically selects the best profiles propeller or wing and inject performance polar for calculations:
Héliciel gives us so quickly, the performance and geometry of a propeller, energy capture, or propulsion. The wings are also calculated by héliciel, taking into account the losses at blade tip. This method is valid only for subsonic speeds where the compression fluid is negligible.
- For more information: methods for calculating wind turbine axial tidal turbine.
- For more information on: methods of calculating propeller fan, water, or aerial