VCE_TNT Module Verification

The VCE TNT model is formulated according model explained in Casal book [Ref.1]. To validate the calculations of this module, example 4.1 of Casal book chose. The following code model the example condition and the final result is checked by example results.

The below codes can be downloaded from here in Jupyter Notebook format.

Verification:

opr.wipe()

#Define Wind Rose
windobj=opr.WindData.WindRose(1)
windobj.WindSpeed=0
windobj.WindDirection=90

#Define Site Condition and Geometry
SiteTAg=1
obj=opr.Sites.Site(SiteTAg, Temperature=16+273, Pressure=1.013*10**5, XSiteBoundary=[0,100,100,0], YSiteBoundary=[0,0,100,100],
                   g=9.81,Humidity=0.79,Airdensity=0.270)

#Define Substance
propane=1
subsobj=opr.Substance.Material(propane,name='Propane',Density=553,GasDensity=1,BoilingPointGasDensity=2.32, Specific_Heat_Ratio=1.15,
                               Molecular_Weight=44.1/1000, Specific_Heat_of_Combustion=43.930*10**6,
                               Lower_Flammability_Limit=0.2, Upper_Flammability_Limit=0.7,)

#Define OutFlow Model
OutflowObj=opr.OutFlowModel.GasUnitHole(tag=1, Hole_Diameter=0.1, Total_t=20, Cd=1, Gas_Constant=8.31446261815324)

#Define Dispersion Model
DispObj=opr.DispersionSpreadModels.BritterMcQuaid(tag=1, MatTags=1, OutFlowModelTags=[1], MassParts=20,)

#Define Dike for Tanks
opr.Safety.Dike(1,0,3.1415*6**2/4)

#Define Plant Unit
PlantObj=opr.PlantUnits.ONGStorage(1,SiteTag=1,DikeTag=1, SubstanceTag=1,  Diameter=10, Pressure= 1.769025*10**5, Temperature=16+273,
                                   Horizontal_localPosition=0,    Vertical_localPosition=0,
                                   Height=20,SubstanceVolumeRatio=0.9)

#Manually define OutFlow Model for above Unit Object
PlantObj.OutFlowModelObject=OutflowObj
OutflowObj.UnitObject=PlantObj
PlantObj.OutFlowModelObject.Calculate()


#Manually define DispersionSpread Model for above Unit Object
PlantObj.DispersionSpreadModelObject=DispObj
PlantObj.DispersionSpreadModelObject.UnitObject=PlantObj
PlantObj.DispersionSpreadModelObject.Calculate()

print("Exposive mass =",DispObj.GasExplosiveMass)
print("Explosive Mass center = ", DispObj.GasExplosiveCenterX,DispObj.GasExplosiveCenterY,DispObj.GasExplosiveCenterZ)



obj=opr.PhysicalEffect.VCE_TNT(1)
obj.UnitObject=PlantObj
obj.Calculate()
dP=obj.OverPressure_at_Point(DispObj.GasExplosiveCenterX[0]+500,0,0)
print("The Over Pressure Value in 500 m Over Explosive mass Center =",dP/10**5, " Bar")

print('in casal Example 4.1, \nd=500 m \nM (Explosive Mass)= 30,000 \nDeltaHc=43930*1000')
print('And the result of over pressure is = 0.049 Bar')
print('That is compatible with the above results!')

The result of above code has been shown in the following:

Exposive mass = [30000.0545780576]
Explosive Mass center =  [205.0062463385579] [0.0] [1.6781175585645267e-07]
The Over Pressure Value in 500 m Over Explosive mass Center = 0.048807472058782414  Bar

in casal Example 4.1,
d=500 m
M (Explosive Mass)= 30,000
DeltaHc=43930*1000
And the result of over pressure is = 0.049 Bar
That is compatible with the above results!

[Ref.1]

J. Casal, Evaluation of the Effects and Consequences of Major Accidents in Industrial Plants, vol. 8. 2018.

Code Developed by: Bijan Sayyafzadeh