Merge pull request #14978 from mcgratta/master

mcgratta · web-flow · commit 9dd97ffcdea0 · 2025-08-17T12:45:27.000-04:00
FDS Verification: Add thick_orifice test case
diff --git a/Manuals/Bibliography/FDS_general.bib b/Manuals/Bibliography/FDS_general.bib
@@ -2996,6 +2996,15 @@ @ARTICLE{Icove:JNAFE2021
   note         = {\href{https://doi.org/10.51501/jotnafe.v38i1.167}{https://doi.org/10.51501/jotnafe.v38i1.167}}
 }
 
+@BOOK{Idelchik:1,
+  author       = {I.E. Idelchik},
+  title        = {Handbook of Hydraulic Resistance},
+  edition      = {3rd},
+  publisher    = {CRC Press},
+  address      = {Boca Raton, Florida},
+  year         = {1994}
+}
+
 @INPROCEEDINGS{Ierardi:1,
   author       = {Ierardi, J.A. and Barnett, J.R.},
   title        = {{A Quantitative Method for Calibrating CFD Model Calculations}},
diff --git a/Manuals/FDS_Verification_Guide/FDS_Verification_Guide.tex b/Manuals/FDS_Verification_Guide/FDS_Verification_Guide.tex
@@ -1596,6 +1596,31 @@ \subsection{1-D Flow in a Tunnel (\texorpdfstring{\ct{tunnel_linear_cp}}{tunnel\
 \label{tunnel_linear_cp_plots}
 \end{figure}
 
+\FloatBarrier
+
+
+\section{Discharge Coefficient}
+\label{thick_orifice}
+
+A useful way to assess the way the model handles velocity boundary conditions at corners is to examine flows through an orifice. Consider a 2~m square duct with a 1~m square orifice. The orifice is $l=0.4$~m wide and has a hydraulic diameter $D_{\rm h}=1$~m. A uniform flow of $w_1=0.5$~m/s is pushed through the duct. According to an empirical correlation presented in Diagram~4-15 of the Handbook of Hydraulic Resistance by Idelchik~\cite{Idelchik:1}, the pressure rise behind the orifice is given by
+\be
+   \Delta p = \frac{1}{2} \zeta_1 \, \rho \, w_1^2 \approx 4.09 \; \mbox{Pa}
+\ee
+where $\zeta_1=27.4$ and the density of air is $\rho=1.195$~kg/m$^3$. Figure~\ref{fig:thick_orifice} displays the pressure along the duct, where the flow is from left to right.
+
+\begin{figure}[!ht]
+\centering
+\includegraphics[height=2.2in]{SCRIPT_FIGURES/thick_orifice}
+\caption[Results of the \ct{thick_orifice} case]{Pressure rise behind an square, thick orifice in a duct.}
+\label{fig:thick_orifice}
+\end{figure}
+
+
+
+
+
+
+
 \chapter{Turbulence}
 
 
diff --git a/Utilities/Matlab/FDS_verification_dataplot_inputs.csv b/Utilities/Matlab/FDS_verification_dataplot_inputs.csv
@@ -702,6 +702,7 @@ d,thermocouples,Radiation/thermocouples_git.txt,Radiation/thermocouples_devc.csv
 d,thermocouple_time_constant,Heat_Transfer/thermocouple_time_constant_git.txt,Heat_Transfer/thermocouple_time_constant.csv,1,2,Time,T_0.5,Exact (0.5 s),ko,0,100000,,0.49,0.51,-1.00E+09,1.00E+09,0,Heat_Transfer/thermocouple_time_constant_devc.csv,2,3,Time,T_0.5,FDS (0.5 s),k-,0,100000,,0.49,0.51,-1.00E+09,1.00E+09,0,Bead Temperature (thermocouple\_time\_constant),Time (s),Temperature (°C),0,20,1,15,35,1,no,0.05 0.90,SouthEast,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/thermocouple_time_constant,Relative Error,max,0.01,Heat Transfer,ro,r,TeX
 f,thermocouple_time_constant,Heat_Transfer/thermocouple_time_constant_git.txt,Heat_Transfer/thermocouple_time_constant.csv,1,2,Time,T_3.0,Exact (3.0 s),ro,0,100000,,2.99,3.01,-1.00E+09,1.00E+09,0,Heat_Transfer/thermocouple_time_constant_devc.csv,2,3,Time,T_3.0,FDS (3.0 s),r-,0,100000,,2.99,3.01,-1.00E+09,1.00E+09,0,Bead Temperature (thermocouple\_time\_constant),Time (s),Temperature (°C),0,20,1,15,35,1,no,0.05 0.90,SouthEast,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/thermocouple_time_constant,Relative Error,max,0.01,Heat Transfer,ro,r,TeX
 f,thermocouple_time_constant,Heat_Transfer/thermocouple_time_constant_git.txt,Heat_Transfer/thermocouple_time_constant.csv,1,2,Time,T_8.0,Exact (8.0 s),go,0,100000,,7.99,8.01,-1.00E+09,1.00E+09,0,Heat_Transfer/thermocouple_time_constant_devc.csv,2,3,Time,T_8.0,FDS (8.0 s),g-,0,100000,,7.99,8.01,-1.00E+09,1.00E+09,0,Bead Temperature (thermocouple\_time\_constant),Time (s),Temperature (°C),0,20,1,15,35,1,no,0.05 0.90,SouthEast,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/thermocouple_time_constant,Relative Error,max,0.01,Heat Transfer,ro,r,TeX
+d,thick_orifice,Pressure_Effects/thick_orifice_5cm_git.txt,Pressure_Effects/thick_orifice.csv,1,2,x,p,Empirical,ko,-100000,100000,,-10000,10000,-1.00E+09,1.00E+09,0,Pressure_Effects/thick_orifice_5cm_line.csv,2,3,x,p,FDS,k-,-100000,100000,,-10000,10000,-1.00E+09,1.00E+09,0,Pressure Rise (thick\_orifice),x (m),Pressure Rise (Pa),-5,11,1,-2,6,1,no,0.05 0.90,East,,1,linear,FDS_Verification_Guide/SCRIPT_FIGURES/thick_orifice,Relative Error,max,0.05,Heat Transfer,ro,r,TeX
 d,test_hrr_2d_cyl,Energy_Budget/test_hrr_2d_cyl_git.txt,Energy_Budget/test_hrr_3d_hrr.csv,2,3,Time,HRR,3D HRR,k--,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Energy_Budget/test_hrr_2d_cyl_hrr.csv,2,3,Time,HRR,2D Cyl HRR,k-,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Heat Release Rate,Time (s),$\dot{Q}$ (kW),0,10,1,0,200,1,no,0.05 0.90,SouthEast,,1,linear,FDS_User_Guide/SCRIPT_FIGURES/test_hrr_2d_cyl,Relative Error,mean,0.01,Energy Budget,m+,m,LaTeX
 d,tmp_lower_limit,Fires/tmp_lower_limit_default_git.txt,Fires/tmp_lower_limit.csv,1,2,Time,T,Expected (min T),ko,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Fires/tmp_lower_limit_default_devc.csv,2,3,Time,minT,FDS (min T),k-,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Temperature Lower Limit (default),Time (s),Temperature (°C),0,1,1,0,40,1,no,0.05 0.90,SouthEast,,1,linear,FDS_Verification_Guide/SCRIPT_FIGURES/tmp_lower_limit_default,Absolute Error,threshold,0.2,Fires,kd,k,TeX
 d,tmp_lower_limit,Fires/tmp_lower_limit_simple_git.txt,Fires/tmp_lower_limit.csv,1,2,Time,T,Expected (min T),ko,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Fires/tmp_lower_limit_simple_devc.csv,2,3,Time,minT,FDS (min T),k-,0,100000,,0,100000,-1.00E+09,1.00E+09,0,Temperature Lower Limit (simple),Time (s),Temperature (°C),0,1,1,0,40,1,no,0.05 0.90,SouthEast,,1,linear,FDS_Verification_Guide/SCRIPT_FIGURES/tmp_lower_limit_simple,Absolute Error,threshold,0.01,Fires,kd,k,TeX
diff --git a/Verification/FDS_Cases.sh b/Verification/FDS_Cases.sh
@@ -415,6 +415,7 @@ $QFDS -d Pressure_Effects isentropic.fds
 $QFDS -d Pressure_Effects isentropic2.fds
 $QFDS -d Pressure_Effects pressure_boundary.fds
 $QFDS -d Pressure_Effects pressure_rise.fds
+$QFDS -p 8 -d Pressure_Effects thick_orifice_5cm.fds
 $QFDS -d Pressure_Effects zone_break_fast.fds
 $QFDS -d Pressure_Effects zone_break_slow.fds
 $QFDS -d Pressure_Effects zone_break_fast_ulmat.fds
diff --git a/Verification/Pressure_Effects/thick_orifice.csv b/Verification/Pressure_Effects/thick_orifice.csv
@@ -0,0 +1,7 @@
+x,p
+-5,4.09
+-4,4.09
+-3,4.09
+-2,4.09
+10,0
+11,0
diff --git a/Verification/Pressure_Effects/thick_orifice_5cm.fds b/Verification/Pressure_Effects/thick_orifice_5cm.fds
@@ -0,0 +1,25 @@
+
+&HEAD CHID='thick_orifice_5cm', TITLE='Flow in square duct through thick baffle' /
+
+&MESH IJK=40,40,40, XB=-1.0,1.0,-1.0,1.0,-1.0,1.0, MULT_ID='mesh' /
+&MULT ID='mesh', DX=2.0, I_LOWER=-2, I_UPPER=5 /
+
+&TIME T_END=30.0 /
+
+&PRES TUNNEL_PRECONDITIONER=T /
+
+&SURF ID='INFLOW', VEL=-0.5, COLOR='BLUE' /
+
+&VENT PBX=-5.0, SURF_ID='INFLOW' /
+&VENT MB='XMAX', SURF_ID='OPEN' /
+
+&OBST XB=-0.20,0.20,-1.0,1.0,-1.0,1.0 /
+&HOLE XB=-0.21,0.21,-0.5,0.5,-0.5,0.5 /
+
+&SLCF PBY=0.00,QUANTITY='PRESSURE', VECTOR=T /
+&SLCF PBY=0.00,QUANTITY='PRESSURE', CELL_CENTERED=T /
+&SLCF PBY=0.00,QUANTITY='VELOCITY', CELL_CENTERED=T /
+
+&DEVC ID='p', XB=-5,11,0,0,0,0, POINTS=100, QUANTITY='PRESSURE', STATISTICS_START=10., X_ID='x' /
+
+&TAIL /

-Original file line number
+Diff line change
@@ @@ -0,0 +1,7 @@ @@
 +x,p
 +-5,4.09
 +-4,4.09
 +-3,4.09
 +-2,4.09
 +10,0
 +11,0