diff --git a/BasicSolver/2D-seq/Makefile b/BasicSolver/2D-seq/Makefile
index 2b144a6..f909c04 100644
--- a/BasicSolver/2D-seq/Makefile
+++ b/BasicSolver/2D-seq/Makefile
@@ -39,11 +39,9 @@ $(BUILD_DIR)/%.s:  %.c
 
 .PHONY: clean distclean tags info asm format
 
-clean:
+clean: viz
 	$(info ===>  CLEAN)
 	@rm -rf $(BUILD_DIR)
-	@rm -f vtk_files/particle*.vtk
-	@rm -f vis_files/particle*.dat
 	@rm -f tags
 
 distclean: clean
diff --git a/BasicSolver/2D-seq/src/vtkWriter.c b/BasicSolver/2D-seq/src/vtkWriter.c
new file mode 100644
index 0000000..5a7cdbf
--- /dev/null
+++ b/BasicSolver/2D-seq/src/vtkWriter.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2022 NHR@FAU, University Erlangen-Nuremberg.
+ * All rights reserved. This file is part of nusif-solver.
+ * Use of this source code is governed by a MIT style
+ * license that can be found in the LICENSE file.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "vtkWriter.h"
+
+static float floatSwap(float f)
+{
+    union {
+        float f;
+        char b[4];
+    } dat1, dat2;
+
+    dat1.f    = f;
+    dat2.b[0] = dat1.b[3];
+    dat2.b[1] = dat1.b[2];
+    dat2.b[2] = dat1.b[1];
+    dat2.b[3] = dat1.b[0];
+    return dat2.f;
+}
+
+static void writeHeader(VtkOptions* o, int ts)
+{
+    fprintf(o->fh, "# vtk DataFile Version 3.0\n");
+    fprintf(o->fh, "PAMPI cfd solver particle tracing file\n");
+    if (o->fmt == ASCII) {
+        fprintf(o->fh, "ASCII\n");
+    } else if (o->fmt == BINARY) {
+        fprintf(o->fh, "BINARY\n");
+    }
+
+    fprintf(o->fh, "DATASET UNSTRUCTURED_GRID\n");
+    fprintf(o->fh, "FIELD FieldData 2\n");
+    fprintf(o->fh, "TIME 1 1 double\n");
+    fprintf(o->fh, "%d\n", ts);
+    fprintf(o->fh, "CYCLE 1 1 int\n");
+    fprintf(o->fh, "1\n");
+}
+
+void vtkOpen(VtkOptions* o, char* problem, int ts)
+{
+    o->fh = fopen(problem, "w");
+
+    if (o->fh == NULL) {
+        printf("vtkWriter not initialize! Call vtkOpen first!\n");
+        exit(EXIT_FAILURE);
+    }
+
+    writeHeader(o, ts);
+
+    printf("Writing VTK output for %s\n", problem);
+}
+
+void vtkParticle(VtkOptions* o, char* name)
+{
+    Particle* particlePool = o->particletracer->particlePool;
+
+    int imax = o->solver->imax;
+    int jmax = o->solver->jmax;
+
+    if (o->fh == NULL) {
+        printf("vtkWriter not initialize! Call vtkOpen first!\n");
+        exit(EXIT_FAILURE);
+    }
+
+    fprintf(o->fh, "POINTS %s float\n", o->particletracer->totalParticles);
+
+
+    for (int i = 0; i < o->particletracer->totalParticles; ++i)
+    {
+        if(particlePool[i].flag == true)
+        {
+            double x = particlePool[i].x;
+            double y = particlePool[i].y;
+            fprintf(o->fh, "%.2f %.2f 0.0\n", x, y);
+        }
+    }
+
+    fprintf(o->fh, "CELLS %.0f float\n", o->particletracer->totalParticles);
+
+
+    for (int i = 0, j = 0; i < o->particletracer->totalParticles; ++i)
+    {
+        if(particlePool[i].flag == true)
+        {
+            fprintf(o->fh, "1 %d\n", j);
+            ++j;
+        }
+    }
+
+    fprintf(o->fh, "CELL_TYPES %.0f\n", o->particletracer->totalParticles);
+
+
+    for (int i = 0; i < o->particletracer->totalParticles; ++i)
+    {
+        if(particlePool[i].flag == true)
+        {
+            fprintf(o->fh, "1\n");
+        }
+    }
+
+    /*
+    for (int k = 0; k < kmax; k++) {
+        for (int j = 0; j < jmax; j++) {
+            for (int i = 0; i < imax; i++) {
+                if (o->fmt == ASCII) {
+                    fprintf(o->fh,
+                        "%f %f %f\n",
+                        G(vec.u, i, j, k),
+                        G(vec.v, i, j, k),
+                        G(vec.w, i, j, k));
+                } else if (o->fmt == BINARY) {
+                    fwrite((float[3]) { floatSwap(G(vec.u, i, j, k)),
+                               floatSwap(G(vec.v, i, j, k)),
+                               floatSwap(G(vec.w, i, j, k)) },
+                        sizeof(float),
+                        3,
+                        o->fh);
+                }
+            }
+        }
+    }
+    if (o->fmt == BINARY) fprintf(o->fh, "\n");
+
+    */
+}
+
+void vtkClose(VtkOptions* o)
+{
+    fclose(o->fh);
+    o->fh = NULL;
+}
diff --git a/BasicSolver/2D-seq/particlePool b/BasicSolver/2D-seq/vis_files/particles_0.dat
similarity index 100%
rename from BasicSolver/2D-seq/particlePool
rename to BasicSolver/2D-seq/vis_files/particles_0.dat
diff --git a/BasicSolver/2D-seq/vis_files/particles_1.dat b/BasicSolver/2D-seq/vis_files/particles_1.dat
new file mode 100644
index 0000000..e69de29
diff --git a/BasicSolver/2D-seq/vis_files/particles_2.dat b/BasicSolver/2D-seq/vis_files/particles_2.dat
new file mode 100644
index 0000000..e69de29
diff --git a/BasicSolver/2D-seq/vtk_files/particles0.vtk b/BasicSolver/2D-seq/vtk_files/particles0.vtk
new file mode 100644
index 0000000..a5c8cbd
--- /dev/null
+++ b/BasicSolver/2D-seq/vtk_files/particles0.vtk
@@ -0,0 +1,12 @@
+# vtk DataFile Version 3.0
+PAMPI cfd solver particle tracing file
+ASCII
+DATASET UNSTRUCTURED_GRID
+FIELD FieldData 2
+TIME 1 1 double
+0
+CYCLE 1 1 int
+1
+POINTS (null) float
+CELLS 0 float
+CELL_TYPES 0
diff --git a/BasicSolver/2D-seq/vtk_files/particles1.vtk b/BasicSolver/2D-seq/vtk_files/particles1.vtk
new file mode 100644
index 0000000..a9ca353
--- /dev/null
+++ b/BasicSolver/2D-seq/vtk_files/particles1.vtk
@@ -0,0 +1,12 @@
+# vtk DataFile Version 3.0
+PAMPI cfd solver particle tracing file
+ASCII
+DATASET UNSTRUCTURED_GRID
+FIELD FieldData 2
+TIME 1 1 double
+1
+CYCLE 1 1 int
+1
+POINTS (null) float
+CELLS 0 float
+CELL_TYPES 0
diff --git a/BasicSolver/2D-seq/vtk_files/particles2.vtk b/BasicSolver/2D-seq/vtk_files/particles2.vtk
new file mode 100644
index 0000000..b08ca9e
--- /dev/null
+++ b/BasicSolver/2D-seq/vtk_files/particles2.vtk
@@ -0,0 +1,12 @@
+# vtk DataFile Version 3.0
+PAMPI cfd solver particle tracing file
+ASCII
+DATASET UNSTRUCTURED_GRID
+FIELD FieldData 2
+TIME 1 1 double
+2
+CYCLE 1 1 int
+1
+POINTS (null) float
+CELLS 0 float
+CELL_TYPES 0
diff --git a/BasicSolver/2D-seq/vtk_files/particles3.vtk b/BasicSolver/2D-seq/vtk_files/particles3.vtk
new file mode 100644
index 0000000..e69de29