Example 9813: Solving blood flow & blood cell distributions in a pulmonary capillary network

This example illustrates the blood flow solution over the pulmonary capillaries of a single alveoli. The method of Huang et al. (2001) is used to solve for blood flow within the previously developed pulmonary capillary mesh (see example 9812). An iterative procedure is used, taking into account the hematocrit (red blood cell (RBC) concentration) and capillary dimensional changes in each segment.

This solution procedure determines the pressure at each junction (node) the flow and RBC concentration in each segment (element), and RBC and neutrophil transit time distributions across the network. The dimensional model is this solution procedure calculates the capillary diameters as a result of the capillary, alveolar and pleural pressures.

Flow solution field (Spectrum: red=maximum flow, dark blue=no flow)

To create an image in order to visualise the results of the simulation, use draw.com.

Developed by Kelly Burrowes, 02/2003.

The comfile run by this example is as follows:

fem;
fem de param;r;capillary;example;
fem de coor 3,1;
fem de regi;r;four;example;
fem de base;r;capillary;example;

fem de node;r;cells;example;
fem de elem;r;cells;example;

fem export node;cells as cells;
fem export elem;cells as cells;

fem group elem 100..107,642..687 as alveolus1;

fem de mesh;r;capillary;example reg 2;
fem update mesh geometry capillary reg 2; #defines capillary diameters etc

fem define equation;r;capillary;example reg 2;
fem define material;r;capillary;example reg 2; 
#fem define time;r;capillary;example reg 2;
fem define initial;r;capillary;example reg 2;
fem define solve;r;capillary;example reg 2;


#Below is for time dependent-boundary condition
#$time_initial=0.00;
#$time_final=1;

#$time_step=0.1;
#$write_out_period=0.1;

#fem export nodes;$time_initial as capillary reg 2;
#fem export elem;$time_initial as capillary reg 2;
#fem export properties;initial as initial reg 2 index 17,11,5;

#for ($time=$time_initial;$time<$time_final;$time=$time+$write_out_period)
#{
#fem solve restart to $time+$write_out_period reg 2 delta_t $time_step;
#fem export properties;$time+$write_out_period as solution reg 2 index 17,11,5;
#}

#Below for single time solution (constant boundary condition)

fem solve from 0 to 1 delta_t 0.5 reg 2; #solves system of equations

fem export node;capillary as capillary reg 2;
fem export elem;capillary as capillary reg 2;

fem export node;solution as solution reg 2 field pressure; #exports pressure solutions as field
#fem export properties;solution as solution reg 2 index 12,7,4 #exports solution properties
fem export properties;flow as solution reg 2 index 12 name flow;
fem export properties;hematocrit as solution reg 2 index 7 name hematocrit;
fem export properties;diameter as solution reg 2 index 4 name diameter
#properties: 12=blood flow 7=vessel hematocrit 4=hydraulic diameter

Additional testing commands:

fem list node solution reg 2

Files used by this example are:

Name               Modified     Size


example_9813.com   14-Dec-2005  1.8k
capillary.exelem   08-Oct-2003  176k
capillary.exnode   26-Aug-2004   87k
capillary.ipbase   27-Feb-2003  3.2k
capillary.ipequa   11-Sep-2007  1.6k
capillary.ipinit   08-Oct-2003  1.0k
capillary.ipmate   29-Apr-2005  974 
capillary.ipmesh   26-Aug-2004  1.8k
capillary.ippara   29-Apr-2005  6.1k
capillary.ipsolv   13-Apr-2007  2.2k
capillary.iptime   27-Feb-2003  854 
cells.exelem       27-Feb-2003  175k
cells.exnode       16-Jun-2003  148k
cells.ipelem       27-Feb-2003  190k
cells.ipnode       27-Feb-2003  313k
diameter.exelem    14-Dec-2005   97k
draw.com           14-Dec-2005  1.2k
flow.exelem        14-Dec-2005   97k
flow.mov           27-Feb-2003  4.7M
four.ipregi        27-Feb-2003  102 
hematocrit.exelem  14-Dec-2005   97k
initial.exelem     27-Feb-2003  197k
movie_sub.com      27-Feb-2003  426 
solution.exelem    29-Apr-2005  197k
solution.exnode    29-Apr-2005   40k
test.com           29-Apr-2005  1.7k
test_output.com    27-Feb-2003   29 
time1.out          29-Apr-2005   18k
transit2.out       29-Apr-2005  281k
transit3.out       29-Apr-2005  112

Download the entire example:

Name                           Modified     Size


examples_9_98_981_9813.tar.gz  12-Sep-2007  3.1M

Testing status by version:

StatusTestedReal time (s)
i686-linux
cmFailureSun Mar 6 00:05:48 20160
last breakSun Jan 16 01:00:00 20112
last successSun Jan 2 01:02:00 201133
cm-debugFailureSun Mar 6 00:09:48 20162
last breakTue Jan 11 03:04:00 20116
last successFri Jan 7 00:51:00 201163
mips-irix
cmSuccessSun Aug 19 03:16:48 2007109
cm-debugSuccessWed Aug 15 05:47:35 2007471
cm-debug-clear-mallocSuccessSat Aug 18 06:06:29 2007475
cm-debug-clear-malloc7SuccessMon Aug 20 05:28:13 2007488
cm64SuccessSun Aug 19 03:18:56 2007122
cm64-debugSuccessTue Aug 21 03:42:05 2007459
cm64-debug-clear-mallocSuccessThu Apr 1 10:58:15 2004184
rs6000-aix
cmSuccessWed Mar 4 01:14:07 200910
cm-debugSuccessMon Mar 2 01:35:14 2009126
cm64SuccessWed Mar 4 01:14:12 200910
cm64-debugSuccessTue Mar 3 01:41:29 2009146
x86_64-linux
cmFailureSun Mar 6 00:01:25 20161
last breakSun Jan 16 00:27:00 20111
last successSun Jan 2 00:27:00 201112
cm-debugFailureSun Mar 6 00:01:25 20161
last breakMon Feb 6 00:45:00 20122
last successFri Jan 7 00:17:00 201127

Testing status by file:

Html last generated: Sun Mar 6 05:50:35 2016

Input last modified: Tue Sep 11 10:53:49 2007

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