Merge pull request #13477 from drjfloyd/master

FDS Verification: Adjust methanol evaporation case with corrected Eq.

Manuals/FDS_User_Guide/FDS_User_Guide.tex

@@ -3066,11 +3066,12 @@ \subsection{Liquid Fuels}
 \subsubsection{Evaporation of a Pure Liquid}
 \label{methanol_evaporation}
 
-An example of liquid evaporation is given by the sample case found in the {\ct Pyrolysis} folder called {\ct methanol\_evaporation.fds}. A 1~m by 1~m pan filled with methanol at $T_\infty=20$~$^\circ$C is exposed to a uniform heat flux, $\dot{q}''=20$~\unit{kW/m^2}. The boiling temperature of methanol is $T_{\rm b}=64.65$~$^\circ$C, its specific heat, $c=2.48$~kJ/(kg$\cdot$K), and heat of vaporization, $h_{\rm v}=1099$~kJ/kg. The evaporation rate of a burning liquid in steady state is approximately
+An example of liquid evaporation is given by the sample case found in the {\ct Pyrolysis} folder called {\ct methanol\_evaporation.fds}. A 1~m by 1~m pan filled with methanol at $T_\infty=20$~$^\circ$C is exposed to a uniform heat flux, $\dot{q}''=20$~\unit{kW/m^2}. The boiling temperature of methanol is $T_{\rm b}=64.65$~$^\circ$C, its specific heat, $c=2.48$~kJ/(kg$\cdot$K), and heat of vaporization, $h_{\rm v}=1099$~kJ/kg. At steady state, the heat balance at the pool surface is
 \be
-   \dot{m}'' \approx \frac{\dot{q}''}{h_{\rm g}}  \quad ; \quad  h_{\rm g} = c (T_{\rm b}-T_\infty) + h_{\rm v}
+   \dot{q}''_{total} - \dot{q}''_{c}= \dot{m}'' h_{\rm v}(T_s)
 \ee
-In this example, the methanol evaporates in an oxygen-depleted atmosphere and no burning occurs. The left hand plot in Fig.~\ref{methanol_evaporation_plot} displays the computed evaporation rate, $\dot{m}''$, versus the ideal, $\dot{q}''/h_{\rm g}$. The former approaches the latter as all of the absorbed energy is used to evaporate the liquid. The right hand plot shows the computed liquid surface temperature versus the liquid boiling temperature.
+
+where $ \dot{q}''_{c}$ is the heat being conducted away from the surface. If $ \dot{q}''_{c}$ is made zero, which can be done by using {\ct BACKING='INSULATED'} and a high thermal conductivity, then the pool surface temperature,$T_s$, will approach the boiling temperature,$T_b$. In this example, the methanol evaporates in an oxygen-depleted atmosphere and no burning occurs. The left hand plot in Fig.~\ref{methanol_evaporation_plot} displays the computed evaporation rate, $\dot{m}''$, versus the ideal, $\dot{q}''_{}total}/h_{\rm v}(T_b)$. The former approaches the latter as all of the absorbed energy is used to evaporate the liquid. The right hand plot shows the computed liquid surface temperature versus the liquid boiling temperature.
 \begin{figure}[!ht]
 \includegraphics[width=3.2in]{SCRIPT_FIGURES/methanol_evaporation_mdot}
 \includegraphics[width=3.2in]{SCRIPT_FIGURES/methanol_evaporation_temp}

Utilities/Matlab/FDS_verification_dataplot_inputs.csv

@@ -405,8 +405,8 @@ d,multiple_reac_hrrpua,Species/multiple_reac_hrrpua_git.txt,Species/multiple_rea
 d,multiple_reac_n_simple,Species/multiple_reac_n_simple_git.txt,Species/multiple_reac_n_simple.csv,1,2,Time,CH4_CO|CH4_H2,Ideal CO|Ideal H2,ko|ro,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Species/multiple_reac_n_simple_devc.csv,2,3,Time,CH4_CO|CH4_H2,FDS CO|FDS H2,k|r,0,100000,,0,100000,-1.00E+09,1.00E+09,0,CH4 Species Mass,Time (s),Mass (kg),0,0.0001,1,0,0.006,1,no,0.03 0.90,East,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/multiple_reac_n_simple_CH4,Relative Error,end,0.01,Species,yd,y,TeX
 d,multiple_reac_n_simple,Species/multiple_reac_n_simple_git.txt,Species/multiple_reac_n_simple.csv,1,2,Time,C3H8_CO|C3H8_H2O,Ideal CO|Ideal H2O,ko|ro,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Species/multiple_reac_n_simple_devc.csv,2,3,Time,C3H8_CO|C3H8_H2O,FDS CO|FDS H2O,k|r,0,100000,,0,100000,-1.00E+09,1.00E+09,0,C3H8 Species Mass,Time (s),Mass (kg),0,0.0001,1,0,0.025,1,no,0.03 0.90,East,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/multiple_reac_n_simple_C3H8,Relative Error,end,0.01,Species,ys,y,TeX
 d,multiple_reac_n_simple,Species/multiple_reac_n_simple_git.txt,Species/multiple_reac_n_simple.csv,1,2,Time,C2H6_CO|C2H6_H2,Ideal CO|Ideal H2O,ko|ro,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Species/multiple_reac_n_simple_devc.csv,2,3,Time,C2H6_CO|C2H6_H2,FDS CO|FDS H2,k|r,0,100000,,0,100000,-1.00E+09,1.00E+09,0,C2H6 Species Mass,Time (s),Mass (kg),0,0.0001,1,0,0.035,1,no,0.03 0.90,East,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/multiple_reac_n_simple_C2H6,Relative Error,end,0.01,Species,yd,y,TeX
-d,methanol_evaporation,Pyrolysis/methanol_evaporation_git.txt,Pyrolysis/methanol_evaporation_devc.csv,2,3,Time,mdot,Computed Evaporation Rate (mdot),k-,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Pyrolysis/methanol_evaporation_devc.csv,2,3,Time,mdot2,Ideal Evaporation Rate (mdot2),k--,0,100000,,800,900,-1.00E+09,1.00E+09,0,Liquid Evaporation (methanol\_evaporation),Time (min),Mass Loss Rate (kg/m²/s),0,15,60,0,0.02,1,no,0.05 0.90,SouthEast,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/methanol_evaporation_mdot,Relative Error,mean,0.02,Pyrolysis,mx,m,TeX
-d,methanol_evaporation,Pyrolysis/methanol_evaporation_git.txt,Pyrolysis/methanol_evaporation.csv,1,2,Time,Tb,Measured Boiling Temperature (Tb),ko,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Pyrolysis/methanol_evaporation_devc.csv,2,3,Time,Tsurf,Surface Temperature (Tsurf),k-,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Liquid Evaporation (methanol\_evaporation),Time (min),Temperature (°C),0,15,60,0,100,1,no,0.05 0.90,SouthEast,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/methanol_evaporation_temp,Relative Error,end,0.015,Pyrolysis,mx,m,TeX
+d,methanol_evaporation,Pyrolysis/methanol_evaporation_git.txt,Pyrolysis/methanol_evaporation_devc.csv,2,3,Time,mdot,Computed Evaporation Rate (mdot),k-,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Pyrolysis/methanol_evaporation_devc.csv,2,3,Time,mdot2,Ideal Evaporation Rate (mdot2),k--,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Liquid Evaporation (methanol\_evaporation),Time (min),Mass Loss Rate (kg/m²/s),0,6,60,0,0.02,1,no,0.05 0.90,SouthEast,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/methanol_evaporation_mdot,Relative Error,end,0.02,Pyrolysis,mx,m,TeX
+d,methanol_evaporation,Pyrolysis/methanol_evaporation_git.txt,Pyrolysis/methanol_evaporation.csv,1,2,Time,Tb,Measured Boiling Temperature (Tb),ko,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Pyrolysis/methanol_evaporation_devc.csv,2,3,Time,Tsurf,Surface Temperature (Tsurf),k-,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Liquid Evaporation (methanol\_evaporation),Time (min),Temperature (°C),0,6,60,0,100,1,no,0.05 0.90,SouthEast,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/methanol_evaporation_temp,Relative Error,end,0.015,Pyrolysis,mx,m,TeX
 d,MO_velocity_profile_stable,Atmospheric_Effects/MO_velocity_profile_stable_git.txt,Atmospheric_Effects/MO_velocity_profile_stable.csv,1,2,z (m),u (m/s),MO profile,k,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Atmospheric_Effects/MO_velocity_profile_stable_line.csv,2,3,z,u,FDS profile,k--,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Monin-Obukhov profile stable,z (m),u (m/s),0,32,1,0,10,1,no,0.03 0.90,SouthEast,,1,linear,FDS_Verification_Guide/SCRIPT_FIGURES/MO_velocity_profile_stable,Relative Error,area,0.05,Flowfields,r>,r,TeX
 d,MO_velocity_profile_unstable,Atmospheric_Effects/MO_velocity_profile_unstable_git.txt,Atmospheric_Effects/MO_velocity_profile_unstable.csv,1,2,z (m),u (m/s),MO profile,k,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Atmospheric_Effects/MO_velocity_profile_unstable_line.csv,2,3,z,u,FDS profile,k--,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Monin-Obukhov profile unstable,z (m),u (m/s),0,32,1,0,15,1,no,0.03 0.90,SouthEast,,1,linear,FDS_Verification_Guide/SCRIPT_FIGURES/MO_velocity_profile_unstable,Relative Error,area,0.05,Flowfields,r>,r,TeX
 d,Morvan_TGA,WUI/Morvan_TGA_git.txt,WUI/Morvan_Data_Mass.csv,1,2,T (C),Normalized Mass (M/M0),Exp (Morvan 2004),k^,0,100000,,0,100000,-1.00E+09,1.00E+09,0,WUI/Morvan_TGA_tga.csv,2,3,Temp,Total Mass,FDS TGA (Total Mass),k-,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Morvan TGA; 1.6 °C/min,Temperature (°C),Normalized Mass,0,700,1,0,1.2,1,no,0.05 0.90,East,,1,linear,FDS_Verification_Guide/SCRIPT_FIGURES/Morvan_TGA_Total_Mass,N/A,mean,0,Needle TGA,kd,k,TeX

Verification/Pyrolysis/methanol_evaporation.csv

@@ -1,11 +1,8 @@
 Time,Tb
 0,64.65
-100,64.65
-200,64.65
+60,64.65
+120,64.65
+180,64.65
+240,64.65
 300,64.65
-400,64.65
-500,64.65
-600,64.65
-700,64.65
-800,64.65
-900,64.65
+360,64.65

Verification/Pyrolysis/methanol_evaporation.fds

@@ -3,7 +3,7 @@
 &MESH IJK=12,12,12, XB=-0.6,0,-0.6,0,0,0.6, MULT_ID='m1'/
 &MULT ID='m1', DX=0.6, DY=0.6, DZ=0.6, I_UPPER=1, J_UPPER=1, K_UPPER=1 / 8 meshes
 
-&TIME T_END=900. /
+&TIME T_END=360. /
 
 &DUMP FLUSH_FILE_BUFFERS=T, DT_PROF=5., DT_DEVC=5., DT_HRR=5. /
 
@@ -14,7 +14,7 @@
       NU_SPEC                = 1.
       SPEC_ID                = 'METHANOL'
       HEAT_OF_REACTION       = 1099
-      CONDUCTIVITY           = 0.2
+      CONDUCTIVITY           = 100
       SPECIFIC_HEAT          = 2.48
       DENSITY                = 796
       ABSORPTION_COEFFICIENT = 1500
@@ -24,7 +24,8 @@
       EMISSIVITY = 1.
       COLOR     = 'YELLOW'
       MATL_ID   = 'METHANOL LIQUID'
-      THICKNESS = 0.1
+      THICKNESS = 0.05
+      BACKING = 'INSULATED'
       EXTERNAL_FLUX=20 /
 
 &MATL ID            = 'STEEL'
@@ -63,7 +64,7 @@
 
 &DEVC XB=-0.50,0.50,-0.50,0.50,0.05,0.05, QUANTITY='TOTAL HEAT FLUX', SPATIAL_STATISTIC='MEAN', ID='qdot' /
 &DEVC XB=-0.50,0.50,-0.50,0.50,0.05,0.05, QUANTITY='MASS FLUX', SPEC_ID='METHANOL', SPATIAL_STATISTIC='MEAN', ID='mdot' /
-&DEVC XB=-0.50,0.50,-0.50,0.50,0.05,0.05, QUANTITY='TOTAL HEAT FLUX', SPATIAL_STATISTIC='MEAN', ID='mdot2', CONVERSION_FACTOR=0.000826 /
+&DEVC XB=-0.50,0.50,-0.50,0.50,0.05,0.05, QUANTITY='TOTAL HEAT FLUX', SPATIAL_STATISTIC='MEAN', ID='mdot2', CONVERSION_FACTOR=0.00091 /
 &DEVC XB=-0.50,0.50,-0.50,0.50,0.05,0.05, QUANTITY='WALL TEMPERATURE', SPATIAL_STATISTIC='MEAN', SURF_ID='METHANOL POOL', ID='Tsurf' /
 &DEVC XB=-0.50,0.50,-0.50,0.50,0.05,0.05, QUANTITY='WALL TEMPERATURE', SPATIAL_STATISTIC='MAX', SURF_ID='METHANOL POOL', ID='Tsurf_max' /