Velocity2DBiotSavart.cpp

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/*--------------------------------*- VM2D -*-----------------*---------------*\
| ##  ## ##   ##  ####  #####   |                            | Version 1.14   |
| ##  ## ### ### ##  ## ##  ##  |  VM2D: Vortex Method       | 2026/03/06     |
| ##  ## ## # ##    ##  ##  ##  |  for 2D Flow Simulation    *----------------*
|  ####  ##   ##   ##   ##  ##  |  Open Source Code                           |
|   ##   ##   ## ###### #####   |  https://www.github.com/vortexmethods/VM2D  |
|                                                                             |
| Copyright (C) 2017-2026 I. Marchevsky, K. Sokol, E. Ryatina, A. Kolganova   |
*-----------------------------------------------------------------------------*
| File name: Velocity2DBiotSavart.cpp                                         |
| Info: Source code of VM2D                                                   |
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| This file is part of VM2D.                                                  |
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\*---------------------------------------------------------------------------*/
 
 
#include "Velocity2DBiotSavart.h"
 
#include "Airfoil2D.h"
#include "Boundary2D.h"
#include "MeasureVP2D.h"
#include "Mechanics2D.h"
#include "StreamParser.h"
#include "Wake2D.h"
#include "World2D.h"
 
#include "BarnesHut.h"
 
using namespace VM2D;
 
VelocityBiotSavart::VelocityBiotSavart(const World2D& W_) :
    Velocity(W_)
{
};
 
VelocityBiotSavart::~VelocityBiotSavart()
{   
};
 
 
inline void ModifyE2(double* ee2, double dst2)
{
    if (dst2 > 0)
    {
        if (dst2 < ee2[0])
        {
            ee2[2] = ee2[1];
            ee2[1] = ee2[0];
            ee2[0] = dst2;
        }//if (dist2<ee2[0])
        else
        {
            if (dst2 < ee2[1])
            {
                ee2[2] = ee2[1];
                ee2[1] = dst2;
            }// if (dist2<ee2[1])
            else
                if (dst2 < ee2[2])
                    ee2[2] = dst2;
        }//else
    }//if (dst2>0)
}
 
 
 
//Вычисление конвективных скоростей и радиусов вихревых доменов в заданном наборе точек от следа
void VelocityBiotSavart::CalcConvVeloToSetOfPointsFromWake(const WakeDataBase& pointsDb, std::vector<Point2D>& velo, std::vector<double>& domainRadius, bool calcVelo, bool calcRadius)
{
    std::vector<Point2D> selfVelo(pointsDb.vtx.size());
    domainRadius.resize(pointsDb.vtx.size());
 
    double cft = IDPI;
 
#pragma warning (push)
#pragma warning (disable: 4101)
    //Локальные переменные для цикла
    Point2D velI;
    Point2D tempVel;
    double dst2eps, dst2;
#pragma warning (pop)
 
    double eps2 = W.getPassport().wakeDiscretizationProperties.eps2;
 
    if (calcVelo)
    {
#pragma omp parallel for default(none) shared(selfVelo, cft, calcVelo, calcRadius, eps2, pointsDb, domainRadius) private(tempVel, velI, dst2, dst2eps) schedule(dynamic, DYN_SCHEDULE)
        for (int i = 0; i < pointsDb.vtx.size(); ++i)
        {
            double ee2[3] = { 10000.0, 10000.0, 10000.0 };
 
            velI.toZero();
 
            const Point2D& posI = pointsDb.vtx[i].r();
 
            for (size_t j = 0; j < W.getWake().vtx.size(); ++j)
            {
                const Point2D& posJ = W.getWake().vtx[j].r();
 
                dst2 = (posI - posJ).length2();
 
                //Модифицируем массив квадратов расстояний до ближайших вихрей из wake
#ifndef TESTONLYVELO
                if (calcRadius)
                    VMlib::ModifyE2(ee2, dst2);
#endif 
 
                const double& gamJ = W.getWake().vtx[j].g();
 
                tempVel.toZero();
                dst2eps = VMlib::boundDenom(dst2, eps2); //Сглаживать надо!!!               
 
                tempVel = { -posI[1] + posJ[1], posI[0] - posJ[0] };
                tempVel *= (gamJ / dst2eps);
                velI += tempVel;
            }
 
            for (size_t j = 0; j < W.getSource().vtx.size(); ++j)
            {
                const Point2D& posJ = W.getSource().vtx[j].r();
                const double& gamJ = W.getPassport().physicalProperties.accelCft(W.getCurrentTime()) * W.getSource().vtx[j].g();
 
                tempVel.toZero();
 
                dst2 = dist2(posI, posJ);
                dst2eps = VMlib::boundDenom(dst2, W.getPassport().wakeDiscretizationProperties.eps2); //Сглаживать надо!!!
 
                tempVel = { posI[0] - posJ[0], posI[1] - posJ[1] };
                tempVel *= (gamJ / dst2eps);
                velI += tempVel;
            }
#ifndef TESTONLYVELO
            if (calcRadius)
            {
                for (size_t s = 0; s < W.getNumberOfBoundary(); ++s)
                {
                    const auto& bou = W.getBoundary(s);
                    //Модифицируем массив квадратов расстояний до ближайших вихрей из virtualWake                   
                    for (size_t j = 0; j < bou.virtualWake.vtx.size(); ++j)
                        ModifyE2(ee2, dist2(posI, bou.virtualWake.vtx[j].r()));
                }
            }
#endif
 
            velI *= cft;
            selfVelo[i] = velI;
 
#ifndef TESTONLYVELO
            if (calcRadius)
                domainRadius[i] = 1.0 * sqrt((ee2[0] + ee2[1] + ee2[2]) / 3.0);
#endif
        }
    }
    else if (calcRadius)
    {
#pragma omp parallel for default(none) shared(selfVelo, cft, calcVelo, calcRadius, pointsDb, domainRadius) private(tempVel, velI, dst2) schedule(dynamic, DYN_SCHEDULE)
        for (int i = 0; i < pointsDb.vtx.size(); ++i)
        {
            double ee2[3] = { 10000.0, 10000.0, 10000.0 };
 
            velI.toZero();
 
            const Point2D& posI = pointsDb.vtx[i].r();
 
            for (size_t j = 0; j < W.getWake().vtx.size(); ++j)
            {
                const Point2D& posJ = W.getWake().vtx[j].r();
 
                dst2 = dist2(posI, posJ);
 
                //Модифицируем массив квадратов расстояний до ближайших вихрей из wake
                VMlib::ModifyE2(ee2, dst2);
            }
 
            for (size_t s = 0; s < W.getNumberOfBoundary(); ++s)
            {
                for (size_t j = 0; j < W.getBoundary(s).virtualWake.vtx.size(); ++j)
                {
                    const Point2D& posJ = W.getBoundary(s).virtualWake.vtx[j].r();
                    dst2 = dist2(posI, posJ);
 
                    //Модифицируем массив квадратов расстояний до ближайших вихрей из virtualWake
                    ModifyE2(ee2, dst2);
                }
            }
 
            domainRadius[i] = 1.0 * sqrt((ee2[0] + ee2[1] + ee2[2]) / 3.0);
        }
    } //else
 
 
    if (calcVelo)
        for (size_t i = 0; i < velo.size(); ++i)
            velo[i] += selfVelo[i];
 
#ifdef USE_CUDA 
    if (calcVelo)
        W.getCuda().CopyMemToDev<double, 2>(velo.size(), (double*)velo.data(), pointsDb.devVelPtr);
    if (calcRadius)
        W.getCuda().CopyMemToDev<double, 1>(domainRadius.size(), domainRadius.data(), pointsDb.devRadPtr);
#endif
 
}//CalcConvVeloToSetOfPointsFromWake(...)
 
 
 
 
#if defined(USE_CUDA)
void VelocityBiotSavart::GPUCalcConvVeloToSetOfPointsFromWake(std::unique_ptr<BHcu::CudaTreeInfo>& cntrTree, const WakeDataBase& pointsDb, std::vector<Point2D>& velo, std::vector<double>& domainRadius, bool calcVelo, bool calcRadius)
{
    if ((&pointsDb == &W.getWake()) || (&pointsDb == &W.getBoundary(0).virtualWake) || (&pointsDb == &W.getMeasureVP().getWakeVP()))
    {
        size_t npt = pointsDb.vtx.size();
        double*& dev_ptr_pt = pointsDb.devVtxPtr;
 
        if ((W.getNumberOfBoundary() > 0) && (&pointsDb == &W.getBoundary(0).virtualWake))
        {
            for (size_t q = 1; q < W.getNumberOfBoundary(); ++q)
                npt += W.getBoundary(q).virtualWake.vtx.size();
        }
 
        const size_t nvt = W.getWake().vtx.size();
        double*& dev_ptr_vt = W.getWake().devVtxPtr;
        const size_t nsr = W.getSource().vtx.size();
        double*& dev_ptr_sr = W.getSource().devVtxPtr;
        const size_t nbou = W.getNumberOfBoundary();
 
        //size_t* const& dev_nPanels = W.getCuda().dev_ptr_nPanels;
        size_t* const& dev_nVortices = W.getCuda().dev_ptr_nVortices;
 
        double** const& dev_ptr_ptr_vtx = W.getCuda().dev_ptr_ptr_vtx;
 
        std::vector<Point2D> Vel(npt);
        std::vector<double> Rad(npt);
        std::vector<Point2D> newV(npt);
 
        double*& dev_ptr_vel = pointsDb.devVelPtr;
        double*& dev_ptr_rad = pointsDb.devRadPtr;
        const double& eps2 = W.getPassport().wakeDiscretizationProperties.eps2;
 
        if (npt > 0)
        {
            cuCalculateConvVeloWake(npt, dev_ptr_pt, nvt, dev_ptr_vt, nsr, dev_ptr_sr, nbou, dev_nVortices, dev_ptr_ptr_vtx, dev_ptr_vel, dev_ptr_rad, eps2, calcVelo, calcRadius);
 
            if (calcVelo)
            {
                W.getCuda().CopyMemFromDev<double, 2>(npt, dev_ptr_vel, (double*)newV.data(), 20);
 
                for (size_t q = 0; q < npt; ++q)
                    Vel[q] = newV[q];
 
                if ((&pointsDb == &W.getWake()) || (&pointsDb == &W.getMeasureVP().getWakeVP()))
                {
                    for (size_t q = 0; q < npt; ++q)
                        velo[q] += Vel[q];
                }//if &pointsDb
            }//if calcVelo
 
            if (calcRadius)
            {
                if ((&pointsDb == &W.getWake()) || (&pointsDb == &W.getMeasureVP().getWakeVP()))
                {
                    Rad.resize(npt);
                    W.getCuda().CopyMemFromDev<double, 1>(npt, dev_ptr_rad, Rad.data(), 211);
 
                    for (size_t q = 0; q < Rad.size(); ++q)
                        domainRadius[q] = Rad[q];
                }//if &pointsDb
            }//if calcRadius
        }//if npt > 0
    }//if &pointsDb
}//GPUCalcConvVeloToSetOfPointsFromWake(...)
#endif