From 377b6596a9cdfb62a261d2cba4c67be3e9d79244 Mon Sep 17 00:00:00 2001
From: "Claudius \"keldu\" Holeksa" <mail@keldu.de>
Date: Mon, 6 Jul 2026 21:50:06 +0200
Subject: Fixing hlbm momentum and fixing the boundary conditions

---
 examples/stokes_drag_particle_2d_fplbm_gpu/sim.cpp | 6 +++---
 examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp  | 6 +++---
 examples/stokes_drag_particle_2d_psm_gpu/sim.cpp   | 6 +++---
 modules/core/c++/hlbm.hpp                          | 2 +-
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/examples/stokes_drag_particle_2d_fplbm_gpu/sim.cpp b/examples/stokes_drag_particle_2d_fplbm_gpu/sim.cpp
index 0a9b2fb..fb31f47 100644
--- a/examples/stokes_drag_particle_2d_fplbm_gpu/sim.cpp
+++ b/examples/stokes_drag_particle_2d_fplbm_gpu/sim.cpp
@@ -216,11 +216,11 @@ saw::error_or<void> step(
 
 		component<T,Desc,cmpt::ZouHeHorizontal<true>,encode::Sycl<saw::encode::Native>> flow_in{
 			[&](){
-				uint64_t target_t_i = 64u;
+				uint64_t target_t_i = 16u;
 				if(t_i.get() < target_t_i){
-					return 1.0 + (0.0002 / target_t_i) * t_i.get();
+					return 1.0 + (0.00002 / target_t_i) * t_i.get();
 				}
-				return 1.0002;
+				return 1.00002;
 			}()
 		};
 		component<T,Desc,cmpt::ZouHeHorizontal<false>,encode::Sycl<saw::encode::Native>> flow_out{1.0};
diff --git a/examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp b/examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp
index 49e6d43..9a04211 100644
--- a/examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp
+++ b/examples/stokes_drag_particle_2d_hlbm_gpu/sim.cpp
@@ -216,11 +216,11 @@ saw::error_or<void> step(
 
 		component<T,Desc,cmpt::ZouHeHorizontal<true>,encode::Sycl<saw::encode::Native>> flow_in{
 			[&](){
-				uint64_t target_t_i = 64u;
+				uint64_t target_t_i = 16u;
 				if(t_i.get() < target_t_i){
-					return 1.0 + (0.0002 / target_t_i) * t_i.get();
+					return 1.0 + (0.00002 / target_t_i) * t_i.get();
 				}
-				return 1.0002;
+				return 1.00002;
 			}()
 		};
 		component<T,Desc,cmpt::ZouHeHorizontal<false>,encode::Sycl<saw::encode::Native>> flow_out{1.0};
diff --git a/examples/stokes_drag_particle_2d_psm_gpu/sim.cpp b/examples/stokes_drag_particle_2d_psm_gpu/sim.cpp
index 9aa27a6..9781691 100644
--- a/examples/stokes_drag_particle_2d_psm_gpu/sim.cpp
+++ b/examples/stokes_drag_particle_2d_psm_gpu/sim.cpp
@@ -235,11 +235,11 @@ saw::error_or<void> step(
 
 		component<T,Desc,cmpt::ZouHeHorizontal<true>,encode::Sycl<saw::encode::Native>> flow_in{
 			[&](){
-				uint64_t target_t_i = 64u;
+				uint64_t target_t_i = 16u;
 				if(t_i.get() < target_t_i){
-					return 1.0 + (0.0002 / target_t_i) * t_i.get();
+					return 1.0 + (0.00002 / target_t_i) * t_i.get();
 				}
-				return 1.0002;
+				return 1.00002;
 			}()
 		};
 		component<T,Desc,cmpt::ZouHeHorizontal<false>,encode::Sycl<saw::encode::Native>> flow_out{1.0};
diff --git a/modules/core/c++/hlbm.hpp b/modules/core/c++/hlbm.hpp
index d57a2e7..9a89697 100644
--- a/modules/core/c++/hlbm.hpp
+++ b/modules/core/c++/hlbm.hpp
@@ -174,7 +174,7 @@ public:
 
 			uint64_t i_opp = dfi::opposite_index[i];
 
-			saw::data<T> dfs_added = dfs.at({i}) + dfs_old_f.at(n_ind_i).at({i_opp});
+			saw::data<T> dfs_added = dfs.at({i}) - dfs_old_f.at(n_ind_i).at({i_opp});
 			saw::data<sch::Scalar<T>> dfs_added_v;
 			dfs_added_v.at({}) = dfs_added;
 			auto ei_dfs = e_i * dfs_added_v;
-- 
cgit v1.2.3