diff --git a/src/VSM/core/Filament.py b/src/VSM/core/Filament.py
index 6d3b88e..7749d37 100644
--- a/src/VSM/core/Filament.py
+++ b/src/VSM/core/Filament.py
@@ -299,7 +299,7 @@ def velocity_3D_trailing_vortex_semiinfinite(
             # determine the three velocity components
             return K * r1XVf
         # if point is on the filament
-        elif jit_norm(r1XVf) / jit_norm(Vf) == 0:
+        elif jit_norm(r1XVf) / jit_norm(Vf) < 1e-12 * epsilon:
             return np.zeros(3)
         # else, if point within core
         else:
diff --git a/src/VSM/core/Solver.py b/src/VSM/core/Solver.py
index cb4a410..83f5c73 100644
--- a/src/VSM/core/Solver.py
+++ b/src/VSM/core/Solver.py
@@ -36,7 +36,7 @@ def __init__(
         max_iterations: int = 5000,
         allowed_error: float = 1e-6,
         relaxation_factor: float = 0.01,
-        core_radius_fraction: float = 1e-20,
+        core_radius_fraction: float = 0.05,  # Following Damiani et al. (2019) https://docs.nrel.gov/docs/fy19osti/72777.pdf
         gamma_loop_type: str = "base",
         gamma_initial_distribution_type: str = "elliptical",
         is_only_f_and_gamma_output: bool = False,