Model finishing

Ü Impeller | Model finishing

The dialog offers different possibilities to design the connection between blade, hub and shroud.

ModelFinishing

Default trimming

default-blade

Default blade trimming (not exact);
model finishing not necessary

Extend blade only

extended-blade

Extend blades through hub, shroud and trailing edge;
for later trimming in a CAD-system

Solid trimming

trimmed-blade

Blade trimming on hub, shroud and trailing edge;
affects only the solids (and solid faces) of Meridian.Flow Domain, Segment and Blade.

Trimming is only possible if the solids of Meridian.Flow Domain and Blade could be created successfully.

Trimming is only possible if the trailing edge is trimmed, i.e.:

•	in Profiles-dialog the design mode "Freeform" with option "TE rounded" (for turbines: "LE rounded") was not chosen.

•	in Edges-dialog for the "Trailing edge" (for turbines: "Leading edge") the design mode "Simple" and the option "Trimmed on outlet" (for turbines: "Trimmed on inlet") was chosen.

Trimming is a time-consuming operation (up to 1 minute or some minutes for impellers with splitter blades).

Because only solids are trimmed, point-based exports cannot take advantage of this operation. In order to avoid unclarity during export, points and surfaces do not remain in their original state, but are extended (see Extend blade only).

Details:

Solid trimming is based on the Segment. If no segment is defined, a segment of type 2 is created temporarily.

Internal workflow:

•	The blades are extended (see Extend blade only)

•	A single blade is trimmed with Meridian.Flow Domain

•	From Meridian.Flow Domain, a segment is cut. In this way the trimmed Segment.Real Geometry is created.

•	CFD Setup option: If there is an Extension or RSI Connection, Segment.Real Geometry is fused with Segment.Extension and Segment.RSI Connection. In this way, Segment.Flow Domain is created.

•	Segment.Flow Domain is copied and rotated in order to create a new Meridian.Flow Domain.

•	CFD Setup option: If Blade projection was chosen, the corresponding projection surfaces are exactly trimmed.

Option: Blade root fillet

filleted-blade

Fillet creation at blade root;
affects only the solids (and solid faces) of Meridian.Flow Domain and Segment.

The fillet radius should not be too large.

Blade-root-fillet-restrictions

Fillet creation is not possible if the fillets of two neighboring blades would meet or if the fillet would protrude beyond the impeller inlet.

Update mode

•

Manual

The 3D-model is updated only after closing the dialog.

•

Automatic

The 3D-model is updated after every design modification automatically.

Symbol in main window

The symbol shows the state of Model-finishing.

	Model finishing is not defined yet.
	The 3D-Model has been updated according to the finishing settings.
	The design has been changed but the 3D-Model is not up to date (not finished) or the model finishing has failed.

Possible warnings

Problem	Possible solutions
Model finishing currently NOT up-to-date
Model finishing was not executed yet; therefore the 3D model is not up-to-date	Open Model finishing and click <OK>.
3D-Error: Finishing failed!
Leading edge very near to inlet	Change Meridional contour: Move leading edge towards outlet.
Inlet (nearly) tangential to hub or shroud	Change Meridional contour: Avoid tangentiality.
3D-Error: Fusing segment solids failed!
Solid creation for RSI Connection (or Extension) failed	Uncheck RSI Connection (or Extension) in the CFD Setup dialog.
3D-Error: Creating new Meridian.FlowDomain from segment failed!
Blades cut the periodic surfaces of the segment	Choose another segment type, e.g. "Around single blade, middle of PS-SS".

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