Xiangyu-Hu / SPHinXsys

I finished the exclusive shape part and test successfully; I can get reversed level-set value of a geometry.
I add two test cases for this,

One case is the dam break with an exclusive triangle inside, with a normal wall, which means I have two different level-set fields, the triangle one with the reversed value, this case works well.
The other case is a flow-around cylinder, with free stream boundary condition, the cylinder is an exclusive shape with reversed level-set vale. The exclusive shape function works well, but since I don't have FSI algorithm on static confinement boundary conditions, the flow after the cylinder will not flow back, check the picture below.

case 1

case 2

It seems that the your handling of the transport velocity formulation for static confinement is not correct.

I think I found the problem, with the static_confinement, at the first moment, the particles around the cylinder is defined as surface particles, so it will not apply the transport velocity correction.

after run some time, the inner particles are also defined as surface particles

I changed the code to implement transport velocity to all the particles around the cylinder, but it still did not work.

@yyc84 you need a right way to indicate the right surface particles so that the particle around the cylinder will not be identified as surface particle.

the code is here.

SPHinXsys/src/shared/particle_dynamics/fluid_dynamics/fluid_surface_inner.h

Lines 68 to 85 in 383f8b9

    
           template <class FreeSurfaceIdentification> 
        
           class SpatialTemporalFreeSurfaceIdentification : public FreeSurfaceIdentification 
        
           { 
        
           public: 
        
           	template <typename... ConstructorArgs> 
        
           	explicit SpatialTemporalFreeSurfaceIdentification(ConstructorArgs &&...args); 
        
           	virtual ~SpatialTemporalFreeSurfaceIdentification(){}; 
        
           	inline void interaction(size_t index_i, Real dt = 0.0); 
        
           	void update(size_t index_i, Real dt = 0.0); 
        
           protected: 
        
           	StdLargeVec<int> previous_surface_indicator_; 
        
           	bool isNearPreviousFreeSurface(size_t index_i); 
        
           }; 
        
           using SpatialTemporalFreeSurfaceIdentificationInner = 
        
           	SpatialTemporalFreeSurfaceIdentification<FreeSurfaceIndicationInner>;

I have implemented this time-space method to detect the surface particle; it seems this is not caused by it

I think I also need to add the "SpatialTemporalFreeSurfaceIdentificationStaticConfinement" to the static confinement boundary condition, to complete the function with wall part

	template <class FreeSurfaceIdentification>
	class SpatialTemporalFreeSurfaceIdentification : public FreeSurfaceIdentification
	{
	public:
	template <typename... ConstructorArgs>
	explicit SpatialTemporalFreeSurfaceIdentification(ConstructorArgs &&...args);
	virtual ~SpatialTemporalFreeSurfaceIdentification(){};

	inline void interaction(size_t index_i, Real dt = 0.0);

	void update(size_t index_i, Real dt = 0.0);

	protected:
	StdLargeVec<int> previous_surface_indicator_;
	bool isNearPreviousFreeSurface(size_t index_i);
	};
	using SpatialTemporalFreeSurfaceIdentificationInner =
	SpatialTemporalFreeSurfaceIdentification<FreeSurfaceIndicationInner>;

Exclusive shape and static confinement boundary condition