Corrected thermal stress mistake for multiple walls

Was using the wrong dQ/dA for outer walls.
cuspaceflight · May 6, 2022 · bee91b5 · bee91b5
1 parent 25f09c5
commit bee91b5
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Showing 5 changed files with 18 additions and 16 deletions.
diff --git a/Introduction to Bamboo.ipynb b/Introduction to Bamboo.ipynb
diff --git a/cusfbamboo/engine.py b/cusfbamboo/engine.py
@@ -1180,7 +1180,7 @@ def steady_heating_analysis(self, num_grid = 1000, counterflow = True, iter_star
         results["info"]["T_exhaust"] = "Exhaust temperature at each position (K). T_exhaust[i] is the value at x[i]. "
         results["info"]["dQ_dx"] = "Heat transfer rate per unit axial length (W/m). dQ_dx[i] is the value at x[i]."
         results["info"]["dQ_dLc"] = "Heat transfer rate per unit length along the cooling channel (W/m) - equal to dQ/dx for 'vertical' channels but not for 'spiral' channels. dQ_dx[i] is the value at x[i]."
-        results["info"]["dQ_dA"] = "Heat transfer rate per unit chamber area (W/m2). dQ_dA[i] is the value at x[i]."
+        results["info"]["dQ_dA"] = "Heat transfer rate per unit chamber area at the innermost wall (W/m2). dQ_dA[i] is the value at x[i]."
         results["info"]["Rdx"] = "Local thermal resistances at each position (K m/W), in the order coolant convection (index 0) --> exhaust convection. R_dx[i] a list of resistances at the value at x[i]"
         results["info"]["rho_coolant"] = "Density of coolant (kg/m3). rho_coolant[i] is the value at x[i]."
         results["info"]["p_coolant"] = "Static pressure of coolant (Pa). p_coolant[i] is the value at x[i]."
@@ -1239,7 +1239,9 @@ def steady_heating_analysis(self, num_grid = 1000, counterflow = True, iter_star
                 poisson = self.walls[j].material.poisson
                 t_w = self.walls[j].thickness(x)
 
-                results["sigma_t_thermal"][i][j] = E * alpha * results["dQ_dA"][i] * t_w / (2 * (1 - poisson) * k)
+                corrected_dQ_dA = results["dQ_dA"][i] * self.geometry.r(x = results["x"][i]) / (D/2)        # Need to get the actual dQ/dA at the local wall radius (the local radius increases as you move out for each wall)
+
+                results["sigma_t_thermal"][i][j] = E * alpha * corrected_dQ_dA * t_w / (2 * (1 - poisson) * k)      
 
                 # Pressure stress from Heister [9]
                 D += t_w / 2        # Average diameter

diff --git a/examples/Cantera Example.ipynb b/examples/Cantera Example.ipynb
@@ -142,13 +142,13 @@
      "name": "stderr",
      "output_type": "stream",
      "text": [
-      "C:\\Users\\Daniel\\anaconda3\\lib\\site-packages\\numpy\\lib\\function_base.py:1073: RuntimeWarning: divide by zero encountered in true_divide\n",
+      "C:\\Users\\Daniel\\AppData\\Roaming\\Python\\Python38\\site-packages\\numpy\\lib\\function_base.py:1215: RuntimeWarning: divide by zero encountered in true_divide\n",
       "  a = -(dx2)/(dx1 * (dx1 + dx2))\n",
-      "C:\\Users\\Daniel\\anaconda3\\lib\\site-packages\\numpy\\lib\\function_base.py:1074: RuntimeWarning: divide by zero encountered in true_divide\n",
+      "C:\\Users\\Daniel\\AppData\\Roaming\\Python\\Python38\\site-packages\\numpy\\lib\\function_base.py:1216: RuntimeWarning: divide by zero encountered in true_divide\n",
       "  b = (dx2 - dx1) / (dx1 * dx2)\n",
-      "C:\\Users\\Daniel\\anaconda3\\lib\\site-packages\\numpy\\lib\\function_base.py:1075: RuntimeWarning: divide by zero encountered in true_divide\n",
+      "C:\\Users\\Daniel\\AppData\\Roaming\\Python\\Python38\\site-packages\\numpy\\lib\\function_base.py:1217: RuntimeWarning: divide by zero encountered in true_divide\n",
       "  c = dx1 / (dx2 * (dx1 + dx2))\n",
-      "C:\\Users\\Daniel\\anaconda3\\lib\\site-packages\\numpy\\lib\\function_base.py:1081: RuntimeWarning: invalid value encountered in add\n",
+      "C:\\Users\\Daniel\\AppData\\Roaming\\Python\\Python38\\site-packages\\numpy\\lib\\function_base.py:1223: RuntimeWarning: invalid value encountered in add\n",
       "  out[tuple(slice1)] = a * f[tuple(slice2)] + b * f[tuple(slice3)] + c * f[tuple(slice4)]\n"
      ]
     },

diff --git a/examples/Simple Engine.ipynb b/examples/Simple Engine.ipynb
@@ -82,13 +82,13 @@
      "name": "stderr",
      "output_type": "stream",
      "text": [
-      "C:\\Users\\Daniel\\anaconda3\\lib\\site-packages\\numpy\\lib\\function_base.py:1073: RuntimeWarning: divide by zero encountered in true_divide\n",
+      "C:\\Users\\Daniel\\AppData\\Roaming\\Python\\Python38\\site-packages\\numpy\\lib\\function_base.py:1215: RuntimeWarning: divide by zero encountered in true_divide\n",
       "  a = -(dx2)/(dx1 * (dx1 + dx2))\n",
-      "C:\\Users\\Daniel\\anaconda3\\lib\\site-packages\\numpy\\lib\\function_base.py:1074: RuntimeWarning: divide by zero encountered in true_divide\n",
+      "C:\\Users\\Daniel\\AppData\\Roaming\\Python\\Python38\\site-packages\\numpy\\lib\\function_base.py:1216: RuntimeWarning: divide by zero encountered in true_divide\n",
       "  b = (dx2 - dx1) / (dx1 * dx2)\n",
-      "C:\\Users\\Daniel\\anaconda3\\lib\\site-packages\\numpy\\lib\\function_base.py:1075: RuntimeWarning: divide by zero encountered in true_divide\n",
+      "C:\\Users\\Daniel\\AppData\\Roaming\\Python\\Python38\\site-packages\\numpy\\lib\\function_base.py:1217: RuntimeWarning: divide by zero encountered in true_divide\n",
       "  c = dx1 / (dx2 * (dx1 + dx2))\n",
-      "C:\\Users\\Daniel\\anaconda3\\lib\\site-packages\\numpy\\lib\\function_base.py:1081: RuntimeWarning: invalid value encountered in add\n",
+      "C:\\Users\\Daniel\\AppData\\Roaming\\Python\\Python38\\site-packages\\numpy\\lib\\function_base.py:1223: RuntimeWarning: invalid value encountered in add\n",
       "  out[tuple(slice1)] = a * f[tuple(slice2)] + b * f[tuple(slice3)] + c * f[tuple(slice4)]\n"
      ]
     },
@@ -176,7 +176,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 5,
    "metadata": {
     "scrolled": false
    },
@@ -199,7 +199,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 6,
    "metadata": {
     "scrolled": false
    },

diff --git a/setup.py b/setup.py
@@ -14,8 +14,8 @@
     name='cusfbamboo',
     author = 'Daniel Gibbons',                 
     author_email = 'daniel.u.gibbons@gmail.com',        
-    version = '0.2.3',
-    license = '	gpl-3.0',
+    version = '0.2.4',
+    license = '	AGPL-3.0',
     packages = find_packages(),
     install_requires = ['numpy', 'matplotlib', 'scipy'],
     description = 'Cooling system modelling for liquid rocket engines',
@@ -26,7 +26,7 @@
         'Development Status :: 4 - Beta',     
         'Intended Audience :: Science/Research',    
         'Topic :: Scientific/Engineering',
-        'License :: OSI Approved :: GNU General Public License v3 (GPLv3)',   
+        'License :: OSI Approved :: GNU Affero General Public License v3',   
         'Programming Language :: Python :: 3'],
     long_description = long_description,
     long_description_content_type='text/markdown'