Added example dir.

Cantera/python/examples/gasdynamics/soundSpeed/.cvsignore

@@ -0,0 +1,9 @@
+Makefile
+runtest
+ct2ctml.log
+diff_out_0.txt
+gri30.xml
+h2o2.xml
+liquidvapor.xml
+output_0.txt
+transport_log.xml

Cantera/python/examples/gasdynamics/soundSpeed/Makefile.in

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+PYTHON_CMD = @PYTHON_CMD@
+
+run:
+	$(PYTHON_CMD) soundSpeed.py
+
+test:
+	./runtest
+clean:
+	rm -f *.log *.csv *.xml
+	./cleanup
+
+# end of file
+

Cantera/python/examples/gasdynamics/soundSpeed/cleanup

@@ -0,0 +1,5 @@
+#!/bin/sh
+#
+/bin/rm -rf equilibrate_log*.html
+/bin/rm -rf .cttmp* ct2ctml.log transport_log.xml vcs_equilibrate_res*.csv \
+            catcomb.csv output_0.txt diff*

Cantera/python/examples/gasdynamics/soundSpeed/output_blessed_0.txt

@@ -0,0 +1,27 @@
+300.0 (351.8253431032507, 351.82507355528588, 351.82739542290631)
+400.0 (408.99770840823857, 404.61002809345359, 404.61285091294371)
+500.0 (450.54302619825074, 450.54285937555824, 450.54565509925817)
+600.0 (491.48780257355469, 491.4825370038858, 491.48548219951857)
+700.0 (527.48987657090606, 528.57720573041479, 528.58025708728178)
+800.0 (562.86514830983003, 562.65546776816757, 562.65862683547061)
+900.0 (594.67376495368228, 594.39229774412308, 594.39567427125155)
+1000.0 (623.17416605630262, 623.19965168989324, 624.39048433713253)
+1100.0 (652.9369222305852, 653.02769201149727, 653.03113456251015)
+1200.0 (680.29435014296382, 680.38364158810828, 680.38717309322192)
+1300.0 (706.48452611858829, 706.62735514685153, 706.63097030129904)
+1400.0 (731.5808296184332, 731.89893594969146, 731.90262480084903)
+1500.0 (755.59155534306024, 756.31710177592834, 756.32084667529398)
+1600.0 (778.45870616284765, 779.98846087343429, 779.99223241247921)
+1700.0 (800.07940727859886, 803.01610907406564, 803.01986287218335)
+1800.0 (820.35486912478905, 825.50782639603528, 825.51150274583313)
+1900.0 (839.26522886850455, 847.58370670756392, 847.5872348799702)
+2000.0 (856.94734148296527, 869.3826755379506, 869.38598378152176)
+2100.0 (873.73203929088027, 891.0670366816438, 891.07006552686937)
+2200.0 (889.93129596650954, 912.8240458097107, 912.82675962077701)
+2300.0 (906.66389430405366, 934.86379554886662, 934.8661884578828)
+2400.0 (923.87652400866909, 957.41372871164208, 957.41582112412163)
+2500.0 (942.11398411476648, 980.71180764818382, 980.71363895431205)
+2600.0 (961.76960984153754, 1005.0022117319121, 1005.003827580195)
+2700.0 (982.98872554210232, 1030.537277736008, 1030.5387240276229)
+2800.0 (1005.8602014954711, 1057.5854507511394, 1057.5867700914928)
+2900.0 (1030.5601847154323, 1086.4371555287519, 1086.4383848570014)

Cantera/python/examples/gasdynamics/soundSpeed/runtest.in

@@ -0,0 +1,47 @@
+#!/bin/sh
+#
+#
+temp_success="1"
+/bin/rm  -f output_0.txt    diff_csv.txt diff_out_0.txt
+
+##########################################################################
+PYTHON_CMD=@PYTHON_CMD@
+prog=soundSpeed.py
+if test ! -f $prog ; then
+   echo $prog ' does not exist'
+   exit -1
+fi
+#################################################################
+#
+CANTERA_DATA=${CANTERA_DATA:=../../../data/inputs}; export CANTERA_DATA
+CANTERA_BIN=${CANTERA_BIN:=../../../bin}
+
+#################################################################
+
+$PYTHON_CMD $prog  > output_0.txt <<+
+1.0
++
+retnStat=$?
+if [ $retnStat != "0" ]
+then
+  temp_success="0"
+  echo "$prog returned with bad status, $retnStat, check output"
+fi
+
+diff -w output_blessed_0.txt output_0.txt > diff_out_0.txt
+retnStat_0=$?
+
+retnTotal=1
+if test $retnStat_0 = "0" 
+then
+  retnTotal=0
+fi
+
+if test $retnTotal = "0"
+then
+  echo "Successful test comparison on "`pwd`
+else
+  echo "Unsuccessful test comparison of txt files on "`pwd` " test"
+  echo "     see diff_outi_0.txt "
+fi
+

Cantera/python/examples/gasdynamics/soundSpeed/soundSpeed.py

@@ -0,0 +1,63 @@
+from Cantera import *
+import math
+
+def equilSoundSpeeds(gas, rtol = 1.0e-6, maxiter = 5000):
+
+    """Returns a tuple containing the equilibrium and frozen sound
+    speeds for a gas with an equilibrium composition.  The gas is
+    first set to an equilibrium state at the temperature and pressure
+    of the gas, since otherwise the equilibrium sound speed is not
+    defined.
+
+    """
+
+    # set the gas to equilibrium at its current T and P
+    gas.equilibrate('TP', rtol = rtol, maxiter = maxiter)
+
+    # save properties
+    s0 = gas.entropy_mass()
+    p0 = gas.pressure()
+    r0 = gas.density()
+
+    # perturb the pressure
+    p1 = p0*1.0001
+
+    # set the gas to a state with the same entropy and composition but
+    # the perturbed pressure
+    gas.set(S = s0, P = p1)
+
+    # save the density for this case for the frozen sound speed
+    rho_frozen = gas.density()
+    
+    # now equilibrate the gas holding S and P constant
+    gas.equilibrate("SP", loglevel=0, rtol = rtol, maxiter = maxiter) # , rtol = 1.0e-3, maxsteps=10000)
+
+    r1 = gas.density()
+
+    # equilibrium sound speed
+    aequil = math.sqrt((p1 - p0)/(r1 - r0));
+
+    # frozen sound speed
+    afrozen = math.sqrt((p1 - p0)/(rho_frozen - r0));
+
+    # compute the frozen sound speed using the ideal gas
+    # expression as a check
+    cp = gas.cp_mass()
+    cv = gas.cv_mass()
+    gamma = cp/cv
+    afrozen2 = math.sqrt(gamma*GasConstant*gas.temperature()
+                     /gas.meanMolecularWeight())
+    return (aequil, afrozen, afrozen2)
+
+
+# test program
+if __name__ == "__main__":
+    
+    gas = GRI30()
+    gas.set(X = 'CH4:1.00, O2:2.0, N2:7.52')
+    for n in range(27):
+        temp = 300.0 + n*100.0
+        gas.set(T = temp, P = OneAtm)
+        print temp, equilSoundSpeeds(gas)
+
+