PEP is a Microsoft Windows based program for the preparation of CFD models. It has a large toolbox of functions intended to make constructing and modifying models an easy process. The user is presented with a visual display of the geometry being manipulated and the execution of all functions is driven interactively using the mouse cursor. The development goal was to present the user with a CAD-like interface for the manipulation of CFD models.
PEP can read existing models in one of many common formats. Alternatively, models can be creating using several lofting functions. PEP does not have the ability to read IGES files or work with surfaces developed in CAD. Instead, PEP is intended as a complement to the AMI Sping product, which can handle such files. PEP was developed for the manipulation of surface grids and the building of MGAERO field grids. Completed models can be written out in one of many common formats for input to CFD codes. Supported input/output 3-D formats include VSAERO, MGAERO, USAERO, PMARC, CMARC, QUADPAN, A230, PAN AIR (A502), TRANAIR (A633), FLO22, PLOT3D, EMM, DXF R12. Supported airfoil formats include MSES, LED, EPPLER, KOO and SD. PEP can also transfer sections directly to Rhinoceros, a surfacing package developed by Robert McNeel and Associates.
The most important PEP functions are section point redistribution, interactive section interpolation (including constant X, Y or Z for MGAERO) and patch intersection calculation. These are accomplished by splining section defining points. A Monotone Spline is the default for these operations, but the user can instruct PEP to use Linear, Cubic, Biquadratic, Bicubic or Biquintic Splines.
Other important functions include: breaking a patch along a section or a section at a point, combining two patches or two sections, swapping rows and columns in a patch, reordering sections in a patch, points in sections or patches in a model. Complete models or portions of the model can be translated, rotated, copied, deleted or mirrored. Portions of the model can be extracted and written to a file or imported and added to the model under construction. Wing tip patches can easily be created. A built-in editor allows the points in a section to be manually edited. Special functions allow the trailing edge thickness of a wing to be changed and the addition of twist and deformation to a wing. Additionally, sections can be smoothed using either a 5-point algorithm or a random resplining algorithm.
Diagnostic functions allow panel normals and patch paneling order to be displayed. Points can be selected to be identified or to have the distance and angles between pairs of points to be calculated. Other functions find the area enclosed by a section, the circle through any three points, section length or the wetted area of a patch. Models can be checked for duplicate patches or zero area panels.
Functions within PEP allow the following axisymmetric bodies to be created: Tangent Ogive, Secant Ogive, Von Karman Ogive, Sears-Haack Body, Haack-Adams Body, Parabolic Spindle, Ellipsoid of Revolution and Power Law Body. Other functions allow airfoils of the following families to be created: NACA 4-digit, NACA 5-digit, NACA 4-digit modified, NACA 5-digit modified, NACA 1-series, NACA 6-series, NACA 6A-series, NASA 6-series modified, Bolkow 4-digit E series, NPL EC series, NPL ECH series, NPL EQ series, NPL EQH series, NAL Sunya series and Biconvex.
A specialized function allows the model to be displayed as a cylindrical projection (azimuth vs. elevation) for field-of-view plots. For aerial applications, the horizon elevation can be displayed and fringe points on the cylindrical projection can be extracted to a file.
A number of MGAERO field grid preparation functions make this task much easier. These functions allow selected grid blocks to be shown, I, J, K locations to be displayed, grid levels 1-3 to be automatically created, new grids to be interactively created, existing grids to be edited, deleted copied, translated or mirrored.
To support the final preparation of CFD input files; there are a number of operating condition calculation functions. These include; atmospheric properties, water properties, airspeed/Mach/q conversion, lift coefficient calculation, Reynolds number calculation, inflow/outflow calculation, actuator disk properties and Cpstar and Cpvac calculation.
PEP makes use of a full .ini file, saving session view, colors, open files and window positions. The screen display can be printed screen in either color or B&W or captured to a .bmp file. PEP also has help screens for every option. The program has been tested to run under Microsoft Windows 95, Windows 98, Windows NT 4.0 (SP3 and 5), Windows 2000, Windows ME and Windows XP. PEP is marketed exclusively by Analytical Methods, Inc.