From 11a3b3b99fbf16dcb732a06b5e162aa33a940f18 Mon Sep 17 00:00:00 2001
From: Will Bainbridge <http://cfd.direct>
Date: Thu, 31 May 2018 16:58:46 +0100
Subject: [PATCH] ConeInjection, ConeNozzleInjection: Synchronised random
 numbers

The use of random numbers for positioning within the cone injection
models has been made consistent across all cores. Some calls have been
synchronised by means of the globalSample methods, whilst others have
been replaced by non-randomised algorithms.

This resolves bug report https://bugs.openfoam.org/view.php?id=2956
---
 .../ConeInjection/ConeInjection.C             | 16 ++------------
 .../ConeNozzleInjection/ConeNozzleInjection.C | 21 ++++---------------
 2 files changed, 6 insertions(+), 31 deletions(-)

diff --git a/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/ConeInjection/ConeInjection.C b/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/ConeInjection/ConeInjection.C
index 5b60e63a5..191f5afc4 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/ConeInjection/ConeInjection.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/ConeInjection/ConeInjection.C
@@ -107,20 +107,8 @@ Foam::ConeInjection<CloudType>::ConeInjection
 
         axis /= mag(axis);
 
-        vector tangent = Zero;
-        scalar magTangent = 0.0;
-
-        cachedRandom& rnd = this->owner().rndGen();
-        while (magTangent < small)
-        {
-            vector v = rnd.sample01<vector>();
-
-            tangent = v - (v & axis)*axis;
-            magTangent = mag(tangent);
-        }
-
-        tanVec1_[i] = tangent/magTangent;
-        tanVec2_[i] = axis^tanVec1_[i];
+        tanVec1_[i] = normalised(perpendicular(axis));
+        tanVec2_[i] = normalised(axis^tanVec1_[i]);
     }
 
     // Set total volume to inject
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/ConeNozzleInjection/ConeNozzleInjection.C b/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/ConeNozzleInjection/ConeNozzleInjection.C
index 921c36e37..d30c57963 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/ConeNozzleInjection/ConeNozzleInjection.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/ConeNozzleInjection/ConeNozzleInjection.C
@@ -173,25 +173,12 @@ Foam::ConeNozzleInjection<CloudType>::ConeNozzleInjection
 
     setFlowType();
 
-    cachedRandom& rndGen = this->owner().rndGen();
-
     // Normalise direction vector
     direction_ /= mag(direction_);
 
     // Determine direction vectors tangential to direction
-    vector tangent = Zero;
-    scalar magTangent = 0.0;
-
-    while(magTangent < small)
-    {
-        vector v = rndGen.sample01<vector>();
-
-        tangent = v - (v & direction_)*direction_;
-        magTangent = mag(tangent);
-    }
-
-    tanVec1_ = tangent/magTangent;
-    tanVec2_ = direction_^tanVec1_;
+    tanVec1_ = normalised(perpendicular(direction_));
+    tanVec2_ = normalised(direction_ ^ tanVec1_);
 
     // Set total volume to inject
     this->volumeTotal_ = flowRateProfile_.integrate(0.0, duration_);
@@ -319,7 +306,7 @@ void Foam::ConeNozzleInjection<CloudType>::setPositionAndCell
 {
     cachedRandom& rndGen = this->owner().rndGen();
 
-    scalar beta = mathematical::twoPi*rndGen.sample01<scalar>();
+    scalar beta = mathematical::twoPi*rndGen.globalSample01<scalar>();
     normal_ = tanVec1_*cos(beta) + tanVec2_*sin(beta);
 
     switch (injectionMethod_)
@@ -335,7 +322,7 @@ void Foam::ConeNozzleInjection<CloudType>::setPositionAndCell
         }
         case imDisc:
         {
-            scalar frac = rndGen.sample01<scalar>();
+            scalar frac = rndGen.globalSample01<scalar>();
             scalar dr = outerDiameter_ - innerDiameter_;
             scalar r = 0.5*(innerDiameter_ + frac*dr);
             position = position_ + r*normal_;