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
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
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
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.
The Excel program can also be used as stand alone
without the cad models using print out templates.