From c9b6b090ca0ff5a4632f84223831ae4b3499fc76 Mon Sep 17 00:00:00 2001
From: Andrew Heather <a.heather@opencfd.co.uk>
Date: Thu, 31 Aug 2017 14:05:05 +0100
Subject: [PATCH] BUG: Corrected Curle analogy implementation.  See #574

---
 src/functionObjects/field/Curle/Curle.C | 2 +-
 src/functionObjects/field/Curle/Curle.H | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/functionObjects/field/Curle/Curle.C b/src/functionObjects/field/Curle/Curle.C
index 200568ef75..fcdcdd05cb 100644
--- a/src/functionObjects/field/Curle/Curle.C
+++ b/src/functionObjects/field/Curle/Curle.C
@@ -99,7 +99,7 @@ bool Foam::functionObjects::Curle::calc()
 
         volScalarField& pDash = tpDash.ref();
         const volVectorField d(scopedName("d"), C - x0_);
-        pDash = 4*mathematical::pi/c0_*(d/magSqr(d) & dfdt);
+        pDash = (d/magSqr(d) & dfdt)/(4.0*mathematical::pi*c0_);
 
         return store(resultName_, tpDash);
     }
diff --git a/src/functionObjects/field/Curle/Curle.H b/src/functionObjects/field/Curle/Curle.H
index 050970a05b..04e9f73112 100644
--- a/src/functionObjects/field/Curle/Curle.H
+++ b/src/functionObjects/field/Curle/Curle.H
@@ -33,7 +33,7 @@ Description
     Curle's analogy is implemented as:
 
     \f[
-        p' = 4 \frac{\pi}{c_0}\frac{\vec d}{|\vec d|^2}\frac{d(F)}{d(t)} 
+        p' = \frac{1}{4 \pi c_0}\frac{\vec d}{|\vec d|^2}\frac{d(F)}{d(t)}
     \f]
 
 
@@ -68,8 +68,8 @@ Usage
         type         | Type name: Curle             | yes      |
         field        | Pressure field name          | no       | p
         result       | Acoustic pressure field name | no       | Curle
-        patches      | Sound generation patch names | yes      | 
-        c0           | Reference speed of sound     | yes      | 
+        patches      | Sound generation patch names | yes      |
+        c0           | Reference speed of sound     | yes      |
     \endtable