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► VOLUTE  Cutwater
The geometry of the cutwater can be designed in this dialog box.
Generally, the cutwater can be designed in three modes: Simple, Fillet or Sharp.
The leading/trailing edge axis ratio specifies the ratio between the minor and major axis length of an ellipse, representing the leading and trailing edge of the splitter.
General 
The wrap angle must be at least 330°. 
Simple 
For cornered spiral cross sections the side position is fixed to the corner position and cannot be modified individually. 
Rounding of cutwater edges (Round edges) is possible only if side position is higher than the position of maximum curvature and if no radial offset is defined. 

Radial offset is available for strictly external volutes with 360° wrap angle only. 

Fillet 
Fillet cutwater is not available for cornered cross sections, either spiral or diffuser. 
Intersection of spiral and diffuser geometry is necessary to create a fillet cutwater. 

Fillet cutwater is usually not possible, if the spiral development is at the beginning very flat and a tangential diffuser with a big end crosssection is chosen. 

For asymmetric spiral cross sections, only nontangential surface transition is available. 

Sharp 
Sharp cutwater is not available for cornered cross sections, either spiral or diffuser. 
Intersection of spiral and diffuser geometry is necessary to create a sharp cutwater. 
Problem 
Possible solutions 

Intersection of Side A1/B1 with Inlet/Outlet 

Cutwater Side A1/B1 face intersects with Inlet/Outlet face. Inlet/Outlet is a virtual face bordering the Volutes's Flow domain. The intersection affects volumetric meshing of the Flow domain, which may result in very small mesh entities and in a non smooth surface in these regions. Generally, the intersection is very small and hardly visible in 3Dmodel. 
Any parameter modification of the Fillet Cutwater affects the geometry of the side patches. Use automatic Surface transition. 
Cutwater is selfintersecting. 

Cutwater faces intersect each other. 
The problem might have various reasons. Therefore, modify spiral, diffuser or cutwater design. E.g. define a flat radius progression at the start of spiral development areas, or change angular position / radial offset of the cutwater. 
Multiple intersection curves between spiral and diffuser. 

Spiral and diffuser may have multiple intersection curves. (red) 
This problem can be solved by manipulating the spiral start position. A single intersection curve is required for generation of sharp and fillet cutwaters. 
3DError: Could not create bounded surface for Cutwater.Patch! 

Parameter side position is disadvantageous. 
The side position should not be too low when edges are rounded. 
3DError: Could not create fillet for Cutwater! Possibly, the fillet radius is too large. 

[for asymmetric volutes] Fillet cannot be created because intersection curve of spiral and diffuser is wavy. 
Modify the Position of end shape in the Diffuser dialog to avoid wavy intersection curve. 
[for asymmetric volutes] Fillet cannot be created because intersection curve of spiral and diffuser is tangential to the sharp diffuser edge. 
Modify Spiral start position
