From 761e4912e14324ccf713b9309336816cd3283b38 Mon Sep 17 00:00:00 2001
From: "Claudius \"keldu\" Holeksa" <mail@keldu.de>
Date: Wed, 1 Jul 2026 00:15:10 +0200
Subject: stokes drag impl and run

---
 examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp | 58 ++++++++++++++---------
 1 file changed, 35 insertions(+), 23 deletions(-)

(limited to 'examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp')

diff --git a/examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp b/examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp
index 81498e2..18b5258 100644
--- a/examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp
+++ b/examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp
@@ -47,8 +47,8 @@ using RhoChunk = Chunk<Scalar<T>, 0u, dim_x, dim_y>;
 template<typename T, typename Desc>
 using MacroStruct = Struct<
 	Member<VelChunk<T,Desc>, "velocity">,
-	Member<VelChunk<T,Desc>, "force">,
 	Member<RhoChunk<T>, "density">,
+	Member<VelChunk<T,Desc>, "force">,
 	Member<ScalarChunk<T,Desc>, "porosity">
 >;
 
@@ -100,7 +100,6 @@ saw::error_or<void> setup_initial_conditions(
 		{{dim_x-1u,0u}},
 		{{dim_x, dim_y}}
 	);
-	// Overwrite with
 	// Inflow
 	iterator<Desc::D>::apply(
 		[&](auto& index){
@@ -158,7 +157,28 @@ saw::error_or<void> setup_initial_conditions(
 		df_f.get_dims(),
 		{{1u,1u}}
 	);
-	
+
+	/*
+	iterator<Desc::D>::apply(
+		[&](auto& index){
+			saw::data<sch::Vector<T,Desc::D>> middle, ind_vec;
+			middle.at({{0u}}) = dim_x * 0.25;
+			middle.at({{1u}}) = dim_y * 0.5;
+
+			ind_vec.at({{0u}}) = index.at({{0u}}).template cast_to<T>();
+			ind_vec.at({{1u}}) = index.at({{1u}}).template cast_to<T>();
+
+			auto dist = middle - ind_vec;
+			auto dist_2 = saw::math::dot(dist,dist);
+			if(dist_2.at({}).get() < dim_y*dim_y*0.01){
+				porous_f.at(index).at({}) = 0.0;
+			}
+		},
+		{},// 0-index
+		df_f.get_dims()
+	);
+	*/
+
 	return saw::make_void();
 }
 
@@ -173,7 +193,9 @@ saw::error_or<void> step(
 	auto& info_f = fields.template get<"info">();
 	auto& porous_f = macros.template get<"porosity">();
 
+	// auto coll_ev = 
 	q.submit([&](acpp::sycl::handler& h){
+		component<T,Desc,cmpt::BGK, encode::Sycl<saw::encode::Native>> bgk{0.8};
 		component<T,Desc,cmpt::Hlbm,encode::Sycl<saw::encode::Native>> collision{0.8};
 		component<T,Desc,cmpt::BounceBack,encode::Sycl<saw::encode::Native>> bb;
 		component<T,Desc,cmpt::AntiBounceBack<0u>,encode::Sycl<saw::encode::Native>> abb;
@@ -181,13 +203,15 @@ saw::error_or<void> step(
 		saw::data<sch::Scalar<T>> eps;
 		eps.at({}).set(1.5f);
 		saw::data<sch::Scalar<T>> rad;
-		rad.at({}).set(dim_y*0.1*0.25);
+		rad.at({}).set(dim_y*0.1/4.0);
 		saw::data<sch::Vector<T,Desc::D>> p_pos;
 		{
 			p_pos.at({{0u}}) = dim_x * 0.5;
 			p_pos.at({{1u}}) = dim_y * 0.5;
 		}
 		component<T,Desc,cmpt::OneParticleAt,encode::Sycl<saw::encode::Native>> opa{p_pos,rad,eps};
+		
+		component<T,Desc,cmpt::ForceGather, encode::Sycl<saw::encode::Native>> fg;
 
 		component<T,Desc,cmpt::ZouHeHorizontal<true>,encode::Sycl<saw::encode::Native>> flow_in{
 			[&](){
@@ -218,21 +242,20 @@ saw::error_or<void> step(
 				case 2u:
 					opa.apply(macros,index,t_i);
 					collision.apply(fields,macros,index,t_i);
+					fg.apply(fields,macros,index,t_i);
 					break;
 				case 3u:
 					flow_in.apply(fields,index,t_i);
-					//equi.apply(fields,index,t_i);
-					collision.apply(fields,macros,index,t_i);
+					// equi.apply(fields,index,t_i);
+					bgk.apply(fields,macros,index,t_i);
 					break;
 				case 4u:
 					flow_out.apply(fields,index,t_i);
 					// equi.apply(fields,index,t_i);
-					collision.apply(fields,macros,index,t_i);
-					break;
+					bgk.apply(fields,macros,index,t_i);
+				break;
 				case 5u:
-					// Corners
 					bb.apply(fields,index,t_i);
-					break;
 				default:
 				break;
 			}
@@ -342,9 +365,7 @@ saw::error_or<void> lbm_main(int argc, char** argv){
 	sycl_q.wait();
 	auto lsd_view = make_view(lbm_sycl_data);
 	auto lsdm_view = make_view(lbm_sycl_macro_data);
-
 	saw::data<sch::UInt64> time_steps{16u*4096ul};
-
 	auto& info_f = lsd_view.template get<"info">();
 
 	for(saw::data<sch::UInt64> i{0u}; i < time_steps and krun; ++i){
@@ -356,8 +377,7 @@ saw::error_or<void> lbm_main(int argc, char** argv){
 			}
 		}
 		sycl_q.wait();
-		/*
-		if(i.get() %  32u == 0u){
+		if(i.get() % 32u == 0u){
 			{
 				auto eov = dev.copy_to_host(lbm_sycl_macro_data,*lbm_macro_data_ptr);
 				if(eov.is_error()){
@@ -365,14 +385,12 @@ saw::error_or<void> lbm_main(int argc, char** argv){
 				}
 			}
 			{
-				auto eov = write_vtk_file(out_dir,"m",i.get(), *lbm_macro_data_ptr);
+				auto eov = write_csv_file(out_dir,"m",i.get(), *lbm_macro_data_ptr);
 				if(eov.is_error()){
 					return eov;
 				}
 			}
 		}
-		*/
-
 		// Stream
 		sycl_q.submit([&](acpp::sycl::handler& h){
 			component<T,Desc,cmpt::Stream,encode::Sycl<saw::encode::Native>> stream;
@@ -412,12 +430,6 @@ saw::error_or<void> lbm_main(int argc, char** argv){
 			return eov;
 		}
 	}
-	{
-		auto eov = write_csv_file(out_dir,"m",time_steps.get(), *lbm_macro_data_ptr);
-		if(eov.is_error()){
-			return eov;
-		}
-	}
 
 	sycl_q.wait();
 	return saw::make_void();
-- 
cgit v1.2.3