From d83d84c5311e6b58c1660acf914a2ae028211e02 Mon Sep 17 00:00:00 2001
From: Martin Bauer <martin.bauer@fau.de>
Date: Sun, 2 Sep 2018 21:14:57 +0200
Subject: [PATCH] Simpler pressure tensor computation
- simplified pressure tensor formulas
- added test that checks if force is mathematically equal if computed from pressure tensor or directly
---
phasefield/analytical.py | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/phasefield/analytical.py b/phasefield/analytical.py
index 5966bb6c..2a6ef6e4 100644
--- a/phasefield/analytical.py
+++ b/phasefield/analytical.py
@@ -301,6 +301,21 @@ def pressure_tensor_interface_component(free_energy, order_parameters, dim, a, b
return result
+def pressure_tensor_interface_component_new(free_energy, order_parameters, dim, a, b):
+ gamma = extract_gamma(free_energy, order_parameters)
+ d = Diff
+ result = 0
+ for i, c_i in enumerate(order_parameters):
+ for j, c_j in enumerate(order_parameters):
+ t = 2 * d(c_i, a) * d(c_j, b)
+ if a == b:
+ t -= sum(d(c_i, g) * d(c_j, g) for g in range(dim))
+ t -= 2 * sum(c_i * d(d(c_j, g), g) for g in range(dim))
+ gamma_ij = gamma[(i, j)] if i < j else gamma[(j, i)]
+ result += t * gamma_ij / 2
+ return result
+
+
def pressure_tensor_from_free_energy(free_energy, order_parameters, dim, transformation_matrix=None,
include_bulk=True, include_interface=True):
--
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