USCSDPM v1.0

Version 1.0 - Unsteady compressible source and doublet panel method

USCSDPM, shortened SDPM, is an implementation of the original source and doublet panel method proposed by Morino (L. Morino and P. Chen, Steady and oscillatory subsonic and supersonic aerodynamics around complex configurations, AIAA Journal, 1975) and revisited by Dimitriadis (M. Martínez and G. Dimitriadis, Subsonic source and doublet panel methods, Journal of Fluids and Structures, 2022). The main purpose of SDPM is to provide steady and unsteady pressure distributions on fixed and moving wings. The code is currently capable of computing steady or unsteady, compressible or incompressible flows on isolated or several wing surfaces.

Features

• C++ code interfaced in Python using SWIG
• Steady or unsteady flows caused by forced harmonic pitching motion of the boundary
• Incompressible or compressible flows
• Isolated or multiple wings

Limitations

• Flow are currently limited to the compressible subsonic, but not transonic regime
• No gradient computation method is currently featured
• Only rigid pitching motion can be currently imposed on the moving boundary

These limitations will be addressed in future developments.

Related issues

• #4 (closed) implemented
• #5 (closed) fixed

Tests

• Ubuntu 22.04 (gcc 11, python 3.10)
• Windows 10 (vs 2022, python 3.8)

sdpm/src/sdpmElement.h

@@ -51,12 +51,15 @@ protected:
     size_t _id;                 ///< element number
     Tag *_tag;                  ///< physical tag to which element belongs
     std::vector<Node *> _nodes; ///< nodes of the element
-    // Flags
-    bool _hasVals; ///< true if (precomputed) values have been initialized
+    bool _toDate;               ///< whether the element values are up-to-date
     // Geometry
-    sdpmVector3d _cg;  ///< element center of gravity
-    sdpmDouble _vol;   ///< element volume
-    sdpmVector3d _nrm; ///< unit normal vector
+    std::vector<sdpmVector3d> _coords; ///< scaled (compressible) coordinates
+    sdpmVector3d _cg0;                 ///< element center of gravity
+    sdpmDouble _srf0;                  ///< element surface area
+    sdpmVector3d _nrm0;                ///< unit normal vector
+    sdpmVector3d _cg;                  ///< compressible element center of gravity
+    sdpmDouble _srf;                   ///< compressible element surface area
+    sdpmVector3d _nrm;                 ///< compressible unit normal vector
 
 public:
 #ifndef SWIG
@@ -70,31 +73,33 @@ public:
     }
 
 #ifndef SWIG
-protected:
-    // Geometry
-    void computeCg();
-    virtual void computeVolume();
-    virtual void computeNormal();
-
-public:
     // Management
-    virtual void init();
-    virtual void update();
+    virtual void update(sdpmDouble beta);
+    // Setters
+    void setNode(size_t i, Node *n) { _nodes[i] = n; }
+#endif
     // Getters
     size_t getId() const { return _id; }
     size_t const &getIdRef() const { return _id; }
     Tag const *getTag() const { return _tag; }
     std::vector<Node *> const &getNodes() const { return _nodes; }
-    inline bool hasValues() const;
-    inline sdpmVector3d const &getCg() const;
-    inline sdpmDouble getVolume() const;
-    inline sdpmVector3d const &getNormal() const;
+    sdpmVector3d const &getCg() const { return _cg0; }
+    sdpmDouble getSurfaceArea() const { return _srf0; }
+    sdpmVector3d const &getNormal() const { return _nrm0; }
+    inline std::vector<sdpmVector3d> const &getCompressibleCoords() const;
+    inline sdpmVector3d const &getCompressibleCg() const;
+    inline sdpmDouble getCompressibleSurfaceArea() const;
+    inline sdpmVector3d const &getCompressibleNormal() const;
+#ifndef SWIG
     // Utilities
+    virtual sdpmVector3d computeGradient(std::vector<sdpmDouble> const &u) const;
     virtual void write(std::ostream &out) const override;
 #endif
 };
 
+#ifndef SWIG
 #include "sdpmElement.inl"
+#endif
 
 } // namespace sdpm