Current version: 3.2        
History of changes          

This parametric program calculates Nasa Bend, Naca Duct and Bellmouth shapes.

The 'NASA Bend' is known as a parametric optimum bending shape for pipe media flow. Variants of the unique shape (red curves in pictures) can often be seen in Formula 1 air intake ducts for manifold optimization, gas turbine exhaust ducts and race head port runners. It minimizes the shear flow in a bended pipe, by other means turbulence and flow resistance.

The 'NACA Duct' is known as an optimum intake duct shape, originally invented in 1945 for aircrafts. It allows air to be drawn into an internal duct with a minimal disturbance to the flow.
The ramp angle and the curvature profile of the walls creates counter-rotating vortices that deflect the boundary layer away from the intake and draws in the faster moving air, while avoiding the form drag and flow separation that can occur with protruding inlet designs. Common applications are race vehicles and aircrafts.

The Bellmouth intake design was investigated and optimized by Prof. G.P Blair and W. Melvin Cahoon in 2006 with respect to maximizing the air flow for intake pulses. This program has a design page that calculates the manufacturing dimensions for different intake pipe sizes.

All these calculation models are included in the program and can be used with Catia V5 3D models that comes with the package. The cad models are parametric and linked to the Excel program, and when ever the Excel program is changed and saved, the cad model will update automatically (with the automatic update setting in Catia). The cad models can however be rebuilt to describe any geometry.

In version 3.2, coordinate data can be exported into a tabular Excel file together with a printed picture for easier CAM manufacturing.

The Excel program is compatible with Windows Vista SP2 or later with installed MS Excel 2003 or later except any trial-, student-, or cloud version (Excel 365).

The Catia V5-6R2012.B22 files contains the parametric surfaces shown below.


The unique section shape is dependent on the pipe diameters and bending radius.

The inlet, outlet and mid section can be rotated in order to create complex shapes. Any combinations can be modeled basically.

Catia is a trademark of Dassault Systemes.

 The software package contains:

 - Bimotion_Flow.xls

 - Bimotion_NASA_Bend.CatPart
 - Bimotion_NACA_Duct#1.CatPart
 - Bimotion_NACA_Duct#2.CatPart

 - Bimotion_Bellmouth.CatPart





Buy the software package now!
Fast delivery by e-mail






US $:49.00

Order is to be placed from Contact in the menu.
System requirements: MS Windows with Excel 2003 or later
(Catia V5-6R2012 or later for models)