Sign convention change for fCap, to be consistent with global framework. Plus...

Sign convention change for fCap, to be consistent with global framework. Plus other minor changes. As discussed in http://www.mail-archive.com/yade-dev@lists.launchpad.net/msg10868.html and http://www.mail-archive.com/yade-dev@lists.launchpad.net/msg10877.html

pkg/dem/CapillaryPhys.hpp

@@ -18,13 +18,13 @@ class CapillaryPhys : public FrictPhys
 		virtual ~CapillaryPhys() {};
 
 	YADE_CLASS_BASE_DOC_ATTRS_DEPREC_INIT_CTOR_PY(CapillaryPhys,FrictPhys,"Physics (of interaction) for :yref:`Law2_ScGeom_CapillaryPhys_Capillarity`.",
-				 ((bool,meniscus,false,,"Presence of a meniscus if true"))
-				 ((bool,isBroken,false,,"If true, capillary force is zero and liquid bridge is inactive."))
+				 ((bool,meniscus,false,Attr::readonly,"True when a meniscus with a non-zero liquid volume (:yref:`vMeniscus<CapillaryPhys.vMeniscus>`) has been computed for this interaction"))
+				 ((bool,isBroken,false,,"Might be set to true by the user to make liquid bridge inactive (capillary force is zero)"))
 				 ((Real,capillaryPressure,0.,,"Value of the capillary pressure Uc. Defined as Ugas-Uliquid, obtained from :yref:`corresponding Law2 parameter<Law2_ScGeom_CapillaryPhys_Capillarity.capillaryPressure>`"))
 				 ((Real,vMeniscus,0.,,"Volume of the meniscus"))
 				 ((Real,Delta1,0.,,"Defines the surface area wetted by the meniscus on the smallest grains of radius R1 (R1<R2)"))
 				 ((Real,Delta2,0.,,"Defines the surface area wetted by the meniscus on the biggest grains of radius R2 (R1<R2)"))
-				 ((Vector3r,fCap,Vector3r::Zero(),,"Capillary force produced by the presence of the meniscus"))
+				 ((Vector3r,fCap,Vector3r::Zero(),,"Capillary force produced by the presence of the meniscus. This is the force acting on particle #2"))
 				 ((short int,fusionNumber,0.,,"Indicates the number of meniscii that overlap with this one"))
 				 ,/*deprec*/
 				 ((Fcap,fCap,"naming convention"))

pkg/dem/CapillaryStressRecorder.hpp

@@ -22,7 +22,7 @@ class CapillaryStressRecorder : public Recorder
 	public :
 		virtual void action();
 		
-	YADE_CLASS_BASE_DOC_ATTRS_CTOR(CapillaryStressRecorder,Recorder,"Records information from capillary meniscii on samples submitted to triaxial compressions. -> New formalism needs to be tested!!!",,initRun=true;);
+	YADE_CLASS_BASE_DOC_ATTRS_CTOR(CapillaryStressRecorder,Recorder,"Records information from capillary meniscii on samples submitted to triaxial compressions. Classical sign convention (tension positiv) is used for capillary stresses. -> New formalism needs to be tested!!!",,initRun=true;);
 	DECLARE_LOGGER;
 
 };

pkg/dem/HertzMindlin.hpp

@@ -179,13 +179,13 @@ class MindlinCapillaryPhys : public MindlinPhys
 		virtual ~MindlinCapillaryPhys() {};
 
 	YADE_CLASS_BASE_DOC_ATTRS_DEPREC_INIT_CTOR_PY(MindlinCapillaryPhys,MindlinPhys,"Adds capillary physics to Mindlin's interaction physics.",
-				((bool,meniscus,false,,"Presence of a meniscus if true"))
-				((bool,isBroken,false,,"If true, capillary force is zero and liquid bridge is inactive."))
+				((bool,meniscus,false,Attr::readonly,"True when a meniscus with a non-zero liquid volume (:yref:`vMeniscus<MindlinPhys.vMeniscus>`) has been computed for this interaction"))
+				((bool,isBroken,false,,"Might be set to true by the user to make liquid bridge inactive (capillary force is zero)"))
 				((Real,capillaryPressure,0.,,"Value of the capillary pressure Uc. Defined as Ugas-Uliquid, obtained from :yref:`corresponding Law2 parameter<Law2_ScGeom_CapillaryPhys_Capillarity.capillaryPressure>`"))
 				((Real,vMeniscus,0.,,"Volume of the meniscus"))
 				((Real,Delta1,0.,,"Defines the surface area wetted by the meniscus on the smallest grains of radius R1 (R1<R2)"))
 				((Real,Delta2,0.,,"Defines the surface area wetted by the meniscus on the biggest grains of radius R2 (R1<R2)"))
-				((Vector3r,fCap,Vector3r::Zero(),,"Capillary Force produces by the presence of the meniscus"))
+				((Vector3r,fCap,Vector3r::Zero(),,"Capillary Force produces by the presence of the meniscus. This is the force acting on particle #2"))
 				((short int,fusionNumber,0.,,"Indicates the number of meniscii that overlap with this one"))
 				,/*deprec*/
 				((Fcap,fCap,"naming convention"))

pkg/dem/Law2_ScGeom_CapillaryPhys_Capillarity.cpp

@@ -109,10 +109,10 @@ void Law2_ScGeom_CapillaryPhys_Capillarity::action()
 			R2=alpha*std::max(currentContactGeometry->radius2,currentContactGeometry->radius1) ;
 
 			/// intergranular distance
-			Real D = alpha*((b2->state->pos-b1->state->pos).norm()-(currentContactGeometry->radius1+ currentContactGeometry->radius2)); // scGeom->penetrationDepth could probably be used here?
+			Real D = - alpha * currentContactGeometry->penetrationDepth;
 
-			if ((currentContactGeometry->penetrationDepth>=0)|| D<=0 || createDistantMeniscii) { //||(scene->iter < 1) ) // a simplified way to define meniscii everywhere
-				D=max(0.,D); // defines fCap when spheres interpenetrate. D<0 leads to wrong interpolation has D<0 has no solution in the interpolation : this is not physically interpretable!! even if, interpenetration << grain radius.
+			if ( D<0 || createDistantMeniscii) { //||(scene->iter < 1) ) // a simplified way to define meniscii everywhere
+				D=max(0.,D); // defines fCap when spheres interpenetrate. D<0 leads to wrong interpolation as D<0 has no solution in the interpolation : this is not physically interpretable!! even if, interpenetration << grain radius.
 				if (!hertzOn) {
 					if (fusionDetection && !cundallContactPhysics->meniscus) bodiesMenisciiList.insert(interaction);
 					cundallContactPhysics->meniscus=true;
@@ -138,7 +138,7 @@ void Law2_ScGeom_CapillaryPhys_Capillarity::action()
 				solution(Pinterpol? capillary->interpolate(R1,R2,Dinterpol, Pinterpol, currentIndexes) : MeniscusParameters());
 				/// capillary adhesion force
 				Real Finterpol = solution.F;
-				Vector3r fCap = Finterpol*(2*Mathr::PI*(R2/alpha)*liquidTension)*currentContactGeometry->normal;
+				Vector3r fCap = - Finterpol*(2*Mathr::PI*(R2/alpha)*liquidTension)*currentContactGeometry->normal;
 				if (!hertzOn) cundallContactPhysics->fCap = fCap;
 				else mindlinContactPhysics->fCap = fCap;
 				/// meniscus volume
@@ -155,7 +155,7 @@ void Law2_ScGeom_CapillaryPhys_Capillarity::action()
 				if (!Vinterpol) {
 					if ((fusionDetection) || (hertzOn ? mindlinContactPhysics->isBroken : cundallContactPhysics->isBroken)) bodiesMenisciiList.remove(interaction);
 					if (D>0) scene->interactions->requestErase(interaction);
-					else LOG_ERROR("No meniscus found at a contact. capillaryPressure may be to large wrt. to the loaded data files.")
+					else LOG_ERROR("No meniscus found at a contact. capillaryPressure may be too large wrt. the loaded data files.")
 				}
 				/// wetting angles
 				if (!hertzOn) {
@@ -197,8 +197,8 @@ void Law2_ScGeom_CapillaryPhys_Capillarity::action()
 					//LINEAR VERSION : capillary force is divided by (fusionNumber + 1) - NOTE : any decreasing function of fusionNumber can be considered in fact
 					else if (fusionNumber !=0) hertzOn?mindlinContactPhysics->fCap:cundallContactPhysics->fCap /= (fusionNumber+1.);
 				}
-				scene->forces.addForce(interaction->getId1(), hertzOn?mindlinContactPhysics->fCap:cundallContactPhysics->fCap);
-				scene->forces.addForce(interaction->getId2(),-(hertzOn?mindlinContactPhysics->fCap:cundallContactPhysics->fCap));
+				scene->forces.addForce(interaction->getId1(),-(hertzOn?mindlinContactPhysics->fCap:cundallContactPhysics->fCap));
+				scene->forces.addForce(interaction->getId2(),  hertzOn?mindlinContactPhysics->fCap:cundallContactPhysics->fCap );
 			}
 		}
 	}