Fixing FpLBM, because I messed up guo forcing

4 files changed, 44 insertions, 8 deletions

diff --git a/examples/schaefer_turek_durst_krause_rannbacher/sim.cpp b/examples/schaefer_turek_durst_krause_rannbacher/sim.cpp
index 4d015c9..ff6a43a 100644
--- a/examples/schaefer_turek_durst_krause_rannbacher/sim.cpp
+++ b/examples/schaefer_turek_durst_krause_rannbacher/sim.cpp
@@ -48,7 +48,7 @@ saw::error_or<void> lbm_main(const saw::data<args::LbmArgs>& args){
 		// delta_x
 		{{0.41 / dim_y}},
 		// delta_t
-		{{1.067e-4}}
+		{{1.067e-4 * 0.5}}
 	};
 	
 	print_lbm_meta<T,Desc>(conv,{1e-3},{1e-4},{0.5 * dim_y});
diff --git a/examples/schaefer_turek_durst_krause_rannbacher/step.hpp b/examples/schaefer_turek_durst_krause_rannbacher/step.hpp
index cbdfd10..9748ec8 100644
--- a/examples/schaefer_turek_durst_krause_rannbacher/step.hpp
+++ b/examples/schaefer_turek_durst_krause_rannbacher/step.hpp
@@ -8,6 +8,7 @@ namespace lbm {
 template<typename T, typename Desc, typename Coll>
 saw::error_or<void> step(
 		const converter<T>& conv,
+		const saw::data<sch::Scalar<T>>& tau,
 		saw::data<sch::Ptr<sch::ChunkStruct<T,Desc>>,encode::Sycl<saw::encode::Native>>& fields,
 		saw::data<sch::Ptr<sch::MacroStruct<T,Desc>>,encode::Sycl<saw::encode::Native>>& macros,
 		saw::data<sch::Ptr<sch::ParticleSpheroidGroup<T,Desc>>,encode::Sycl<saw::encode::Native>>& particles,
@@ -48,7 +49,7 @@ saw::error_or<void> step(
 		}).wait();
 
 		q.submit([&](acpp::sycl::handler& h){
-			component<T,Desc,cmpt::Hlbm,encode::Sycl<saw::encode::Native>> collision{1.0};
+			component<T,Desc,cmpt::Hlbm,encode::Sycl<saw::encode::Native>> collision{0.75};
 			component<T,Desc,cmpt::BounceBack,encode::Sycl<saw::encode::Native>> bb;
 			component<T,Desc,cmpt::ZouHeHorizontal<false>,encode::Sycl<saw::encode::Native>> flow_out{1.0};
 
@@ -74,9 +75,19 @@ saw::error_or<void> step(
 							component<T,Desc,cmpt::ZouHeVelocityX<true>,encode::Sycl<saw::encode::Native>> flow_in{
 								[&]() -> saw::data<sch::Vector<T,Desc::D>> {
 									saw::data<sch::Vector<T,Desc::D>> vel;
+									saw::data<T> scale;
+									{
+										scale.set([&](){
+											if(t_i.get() > 2048u){
+												return 1.0f;
+											}
+
+											return t_i.get() / 2048.0f;
+										}());
+									}
 									{
 										auto y_si = conv.meter_lbm_to_si(index.at({{1u}}).template cast_to<T>()).handle();
-										vel.at({{0u}}) = conv.velocity_si_to_lbm({{static_cast<typename saw::native_data_type<T>::type>((1.2 / 0.41) * y_si.get() - (1.2 / (0.41*0.41)) * y_si.get() * y_si.get())}}).handle();
+										vel.at({{0u}}) = conv.velocity_si_to_lbm({{static_cast<typename saw::native_data_type<T>::type>((1.2 / 0.41) * y_si.get() - (1.2 / (0.41*0.41)) * y_si.get() * y_si.get())}}).handle() * scale;
 										vel.at({{1u}}) = 0.0f;
 									}
 									return vel;
@@ -123,8 +134,8 @@ saw::error_or<void> step(
 
 		// auto coll_ev = 
 		q.submit([&](acpp::sycl::handler& h){
-			component<T,Desc,cmpt::BGK,encode::Sycl<saw::encode::Native>> bgk{1.0};
-			component<T,Desc,cmpt::FpLbm,encode::Sycl<saw::encode::Native>> collision{1.0};
+			component<T,Desc,cmpt::BGK,encode::Sycl<saw::encode::Native>> bgk{0.75};
+			component<T,Desc,cmpt::FpLbm,encode::Sycl<saw::encode::Native>> collision{0.75};
 			component<T,Desc,cmpt::BounceBack,encode::Sycl<saw::encode::Native>> bb;
 			component<T,Desc,cmpt::ZouHeHorizontal<false>,encode::Sycl<saw::encode::Native>> flow_out{1.0};
 
@@ -199,8 +210,8 @@ saw::error_or<void> step(
 
 		// auto coll_ev = 
 		q.submit([&](acpp::sycl::handler& h){
-			component<T,Desc,cmpt::BGK,encode::Sycl<saw::encode::Native>> bgk{1.0};
-			component<T,Desc,cmpt::Psm,encode::Sycl<saw::encode::Native>> collision{1.0};
+			component<T,Desc,cmpt::BGK,encode::Sycl<saw::encode::Native>> bgk{0.75};
+			component<T,Desc,cmpt::Psm,encode::Sycl<saw::encode::Native>> collision{0.75};
 			component<T,Desc,cmpt::BounceBack,encode::Sycl<saw::encode::Native>> bb;
 			component<T,Desc,cmpt::ZouHeHorizontal<false>,encode::Sycl<saw::encode::Native>> flow_out{1.0};
 
diff --git a/modules/core/c++/fplbm.hpp b/modules/core/c++/fplbm.hpp
index c9ed6e9..d8c075b 100644
--- a/modules/core/c++/fplbm.hpp
+++ b/modules/core/c++/fplbm.hpp
@@ -92,7 +92,7 @@ public:
 		auto& force_f = macros.template get<"force">();
 		auto& force = force_f.at(index);
 
-		vel = vel + force * half;
+		vel = vel + force * half / rho;
 
 		// compute_rho_u<T,Descriptor>(dfs,rho,vel);
 		auto eq = equilibrium<T,Descriptor>(rho,vel);
diff --git a/modules/core/c++/macroscopic.hpp b/modules/core/c++/macroscopic.hpp
index 768fef0..9db1538 100644
--- a/modules/core/c++/macroscopic.hpp
+++ b/modules/core/c++/macroscopic.hpp
@@ -33,5 +33,30 @@ void compute_rho_u (
 		vel().at({{i}}) = vel().at({{i}}) / rho().at({});
 	}
 }
+
+/**
+ * Calculate the macroscopic variables rho and u in Lattice Units.
+ */
+template<typename T, typename Desc>
+void compute_rho_momentum (
+		const saw::data<sch::FixedArray<T,Desc::Q>>& dfs,
+		saw::ref<saw::data<sch::Scalar<T>>> rho,
+		saw::ref<saw::data<sch::Vector<T,Desc::D>>> mom
+	)
+{
+	using dfi = df_info<T, Desc>;
+
+	rho().at({}).set(0);
+	for(uint64_t i = 0; i < Desc::D; ++i){
+		mom().at({{i}}).set(0);
+	}
+
+	for(size_t j = 0; j < Desc::Q; ++j){
+		rho().at({}) = rho().at({}) + dfs.at({j});
+		for(size_t i = 0; i < Desc::D; ++i){
+			mom().at({{i}}) = mom().at({{i}}) + saw::data<T>{static_cast<typename saw::native_data_type<T>::type>(dfi::directions[j][i])} * dfs.at({j});
+		}
+	}
+}
 }
 }