Existing panel methods for the prediction of aerodynamic
characteristics have been in widespread use within the aerospace industry
for the last 20 years. They remain by far the most practical tool for the
analysis of complex 3D configurations at subsonic speeds, with a mass of
validated data from a range of applications confirming their accuracy and
versatility. Since the introduction of these codes, however, significant
advances have been made in solution procedures and computer technology.
The basic formulation of NEWPAN is similar to other well established
panel methods. The surface of the vehicle is represented by a set of
abutting facets or panels, each carrying a constant source and/or
doublet singularity distribution. NEWPAN uses a combined boundary
condition formulation to distinguish between two types of components -
thin and thick. The thin (two sided) component carries doublet
singularities and has a Neumann boundary condition imposed; the thick
(single sided) component carries both source and doublet singularities
and has a Dirichlet boundary condition imposed.
Each panel may be quadrilateral or triangular, and thick or
thin. Hence a hybrid surface grid may be utilised, using a mixture of
structured components composed of quadrilateral panels and
unstructured components composed of either triangular or quadrilateral
panels, or both. The flexibility and ease of generation of
unstructured grids makes them ideal for the modelling of complex
configurations where a fully structured surface grid would be time
consuming to generate. Structured grids are ideal for components such
as wings where there is typically high surface curvature in one
direction only, and where an optimum panel distribution leads
naturally to quadrilateral panels of moderate to high aspect ratio. A
hybrid model featuring selective use of structured and unstructured
components achieves the best of both worlds.
In common with other panel methods, the core NEWPAN method is
restricted to the computation of inviscid, incompressible,
irrotational flow. Iterative compressibility corrections extend its
applicability to high subsonic Mach numbers. Boundary layer solvers
provide viscous prediction and correction. A non-coupled integral
boundary layer calculation procedure known as PANBL provides robust
and accurate predictions of flow transition and separation. Its use
with NEWPAN provides a proven method for aerofoil design where gross
flow separation is to be avoided. A strongly coupled
quasi-simultaneous viscous-inviscid procedure, capable of predictions
up to and beyond Clmax is also available for use in conjunction with
NEWPAN has been developed using modern, object-oriented programming
techniques which benefit both developers and users alike. For instance,
NEWPAN has no limit placed upon the maximum problem size; all arrays
are dynamically allocated in C++ as opposed to older rival codes
written in Fortran.
Panel method solutions to the flow about complex configurations are
inherently fast, especially in comparison to volume based
methods. NEWPAN is especially fast; it features a novel accelerated
block-iterative matrix solver and solutions in parallel on
multiprocessor systems. The solution to the complete Formula One car
shown here is obtained in about two minutes on a typical single CPU
The speed, accuracy, flexibility and ease of use of NEWPAN allows
CFD to become an integral part of the design process. Flow Solutions
have always placed strong emphasis on providing engineers with tools
for design, above and beyond analysis. For example:
NEWPAN has a wide customer base, in particular in the following industries:
- the use of inverse design (prescribe a pressure distribution/boundary
layer development and compute the shape necessary to achieve it) as
provided by NEWPAN2D
- the integration of NEWPAN with 3D optimisers (viable even for the
optimisation of complex configurations thanks to the extremely rapid
execution of NEWPAN);
- the coupling of NEWPAN with finite element structural solvers for
the solution of aeroelastic problems (again benefitting from the
rapid execution of the NEWPAN solver).
- aerospace: widely used by QinetiQ (formerly DERA, the UK Government
agency for aerospace evaluation and research) at several
establishments. Extensive validation work has been performed;
- automotive, especially motor racing. NEWPAN has established almost
complete dominance as the panel method of choice in Formula One aerodynamic
design (often complemented by a Navier Stokes code).
- marine: adopted in a range of applications from military submersibles
to yacht racing, in particular the America's Cup. NEWPAN and its derivative
PANSAIL provide solutions both above and below the waterline (e.g. hulls,
keels and sails).
NEWPAN solution on full F1 car with unstructured
end plate grids.
NEWPAN solution on high-lift test configuration.
Quasi-unsteady NEWPAN solution on a blue whale.
NEWPAN solution on an isolated wing,
rolling at 10 degrees per second.
NEWPAN solution on a yacht hull,
modelled with free surface.