src/math/Triangle.cpp

/* Copyright (c) 2008 The University of Notre Dame. All Rights Reserved.
 *
 * The University of Notre Dame grants you ("Licensee") a
 * non-exclusive, royalty free, license to use, modify and
 * redistribute this software in source and binary code form, provided
 * that the following conditions are met:
 *
 * 1. Acknowledgement of the program authors must be made in any
 *    publication of scientific results based in part on use of the
 *    program.  An acceptable form of acknowledgement is citation of
 *    the article in which the program was described (Matthew
 *    A. Meineke, Charles F. Vardeman II, Teng Lin, Christopher
 *    J. Fennell and J. Daniel Gezelter, "OOPSE: An Object-Oriented
 *    Parallel Simulation Engine for Molecular Dynamics,"
 *    J. Comput. Chem. 26, pp. 252-271 (2005))
 *
 * 2. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 3. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the
 *    distribution.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. All express or implied conditions, representations and
 * warranties, including any implied warranty of merchantability,
 * fitness for a particular purpose or non-infringement, are hereby
 * excluded.  The University of Notre Dame and its licensors shall not
 * be liable for any damages suffered by licensee as a result of
 * using, modifying or distributing the software or its
 * derivatives. In no event will the University of Notre Dame or its
 * licensors be liable for any lost revenue, profit or data, or for
 * direct, indirect, special, consequential, incidental or punitive
 * damages, however caused and regardless of the theory of liability,
 * arising out of the use of or inability to use software, even if the
 * University of Notre Dame has been advised of the possibility of
 * such damages.
 *
 *
 *  Triangle.cpp
 *
 *  Purpose: Provide basic triangle object for OOPSE
 *
 *  Created by Charles F. Vardeman II on 29 July 2008.
 *  @author  Charles F. Vardeman II
 *  @version $Id: Triangle.cpp,v 1.3 2009-05-13 22:27:29 gezelter Exp $
 *
 */

#include "math/Triangle.hpp"

using namespace oopse;


Triangle::Triangle() : HaveNormal_(false), HaveCentroid_(false),
                       HaveArea_(false), area_(0.0), normal_(V3Zero), 
                       centroid_(V3Zero), facetVelocity_(V3Zero), mass_(0.0),
                       a_(V3Zero), b_(V3Zero), c_(V3Zero){
}

void Triangle::addVertices(Vector3d P1, Vector3d P2, Vector3d P3){
  vertices_[0] = P1;
  vertices_[1] = P2;
  vertices_[2] = P3;

  // Compute some quantites like a,b,c
  a_ = P1-P2;
  b_ = P1-P3;
  c_ = P2-P3;  
}


RealType Triangle::computeArea(){
  HaveArea_ = true;
  area_ = getNormal().length() * 0.5;
  return area_;
}

Vector3d Triangle::computeNormal(){
  HaveNormal_ = true;
  normal_ = cross(a_,b_);
  return normal_;
}

Vector3d Triangle::computeCentroid(){
  HaveCentroid_ = true;
  centroid_ = (vertices_[0] + vertices_[1] + vertices_[2])/3.0;
  return centroid_;
}


Mat3x3d Triangle::computeHydrodynamicTensor(RealType viscosity) {
  
  Vector3d u0 = -a_;
  Vector3d v0 = centroid_ - vertices_[0];
  RealType s0 = 0.5*cross(u0,v0).length();
  
  Vector3d u1 = -c_;
  Vector3d v1 = centroid_ - vertices_[1];
  RealType s1 = 0.5*cross(u1,v1).length();
  
  Vector3d u2 = b_;
  Vector3d v2 = centroid_ - vertices_[2];
  RealType s2 = 0.5*cross(u2,v2).length();
  
  Mat3x3d H;
  H = hydro_tensor(centroid_,centroid_,vertices_[1],vertices_[0],s0,viscosity)+
    hydro_tensor(centroid_,centroid_,vertices_[1],vertices_[2],s1,viscosity)+
    hydro_tensor(centroid_,centroid_,vertices_[2],vertices_[0],s2,viscosity);

  return H.inverse();
}

Mat3x3d Triangle::hydro_tensor(
                               const Vector3d& ri,
                               const Vector3d& rj0,
                               const Vector3d& rj1,
                               const Vector3d& rj2,
                               RealType s, RealType viscosity){
  
  Vector3d v2 = (rj0 + rj1 + rj2)/3.0;  // sub-centroid
  Vector3d dr = ri - v2;                // real centroid to sub-centroid
  RealType l2 = 1.0/dr.lengthSquare();  
 
  Mat3x3d G;
  G = (SquareMatrix3<RealType>::identity() + outProduct(dr,dr)*l2)*sqrt(l2);

  G *= 0.125/3.14159285358979;
  G *= s/viscosity;
  return G;
}
Revision:	3504
Committed:	Wed May 13 22:27:29 2009 UTC (15 years, 1 month ago) by gezelter
File size:	4511 byte(s)
Log Message:	Adding boundary element hydrodynamics to SMIPD.
#	Content
1	/* Copyright (c) 2008 The University of Notre Dame. All Rights Reserved.
2	*
3	* The University of Notre Dame grants you ("Licensee") a
4	* non-exclusive, royalty free, license to use, modify and
5	* redistribute this software in source and binary code form, provided
6	* that the following conditions are met:
7	*
8	* 1. Acknowledgement of the program authors must be made in any
9	* publication of scientific results based in part on use of the
10	* program. An acceptable form of acknowledgement is citation of
11	* the article in which the program was described (Matthew
12	* A. Meineke, Charles F. Vardeman II, Teng Lin, Christopher
13	* J. Fennell and J. Daniel Gezelter, "OOPSE: An Object-Oriented
14	* Parallel Simulation Engine for Molecular Dynamics,"
15	* J. Comput. Chem. 26, pp. 252-271 (2005))
16	*
17	* 2. Redistributions of source code must retain the above copyright
18	* notice, this list of conditions and the following disclaimer.
19	*
20	* 3. Redistributions in binary form must reproduce the above copyright
21	* notice, this list of conditions and the following disclaimer in the
22	* documentation and/or other materials provided with the
23	* distribution.
24	*
25	* This software is provided "AS IS," without a warranty of any
26	* kind. All express or implied conditions, representations and
27	* warranties, including any implied warranty of merchantability,
28	* fitness for a particular purpose or non-infringement, are hereby
29	* excluded. The University of Notre Dame and its licensors shall not
30	* be liable for any damages suffered by licensee as a result of
31	* using, modifying or distributing the software or its
32	* derivatives. In no event will the University of Notre Dame or its
33	* licensors be liable for any lost revenue, profit or data, or for
34	* direct, indirect, special, consequential, incidental or punitive
35	* damages, however caused and regardless of the theory of liability,
36	* arising out of the use of or inability to use software, even if the
37	* University of Notre Dame has been advised of the possibility of
38	* such damages.
39	*
40	*
41	* Triangle.cpp
42	*
43	* Purpose: Provide basic triangle object for OOPSE
44	*
45	* Created by Charles F. Vardeman II on 29 July 2008.
46	* @author Charles F. Vardeman II
47	* @version $Id: Triangle.cpp,v 1.3 2009-05-13 22:27:29 gezelter Exp $
48	*
49	*/
50
51	#include "math/Triangle.hpp"
52
53	using namespace oopse;
54
55
56	Triangle::Triangle() : HaveNormal_(false), HaveCentroid_(false),
57	HaveArea_(false), area_(0.0), normal_(V3Zero),
58	centroid_(V3Zero), facetVelocity_(V3Zero), mass_(0.0),
59	a_(V3Zero), b_(V3Zero), c_(V3Zero){
60	}
61
62	void Triangle::addVertices(Vector3d P1, Vector3d P2, Vector3d P3){
63	vertices_[0] = P1;
64	vertices_[1] = P2;
65	vertices_[2] = P3;
66
67	// Compute some quantites like a,b,c
68	a_ = P1-P2;
69	b_ = P1-P3;
70	c_ = P2-P3;
71	}
72
73
74	RealType Triangle::computeArea(){
75	HaveArea_ = true;
76	area_ = getNormal().length() * 0.5;
77	return area_;
78	}
79
80	Vector3d Triangle::computeNormal(){
81	HaveNormal_ = true;
82	normal_ = cross(a_,b_);
83	return normal_;
84	}
85
86	Vector3d Triangle::computeCentroid(){
87	HaveCentroid_ = true;
88	centroid_ = (vertices_[0] + vertices_[1] + vertices_[2])/3.0;
89	return centroid_;
90	}
91
92
93	Mat3x3d Triangle::computeHydrodynamicTensor(RealType viscosity) {
94
95	Vector3d u0 = -a_;
96	Vector3d v0 = centroid_ - vertices_[0];
97	RealType s0 = 0.5*cross(u0,v0).length();
98
99	Vector3d u1 = -c_;
100	Vector3d v1 = centroid_ - vertices_[1];
101	RealType s1 = 0.5*cross(u1,v1).length();
102
103	Vector3d u2 = b_;
104	Vector3d v2 = centroid_ - vertices_[2];
105	RealType s2 = 0.5*cross(u2,v2).length();
106
107	Mat3x3d H;
108	H = hydro_tensor(centroid_,centroid_,vertices_[1],vertices_[0],s0,viscosity)+
109	hydro_tensor(centroid_,centroid_,vertices_[1],vertices_[2],s1,viscosity)+
110	hydro_tensor(centroid_,centroid_,vertices_[2],vertices_[0],s2,viscosity);
111
112	return H.inverse();
113	}
114
115	Mat3x3d Triangle::hydro_tensor(
116	const Vector3d& ri,
117	const Vector3d& rj0,
118	const Vector3d& rj1,
119	const Vector3d& rj2,
120	RealType s, RealType viscosity){
121
122	Vector3d v2 = (rj0 + rj1 + rj2)/3.0; // sub-centroid
123	Vector3d dr = ri - v2; // real centroid to sub-centroid
124	RealType l2 = 1.0/dr.lengthSquare();
125
126	Mat3x3d G;
127	G = (SquareMatrix3<RealType>::identity() + outProduct(dr,dr)l2)sqrt(l2);
128
129	G *= 0.125/3.14159285358979;
130	G *= s/viscosity;
131	return G;
132	}