Discussion Forum

Good day everyone. I am an undergraduate chemical engineering student in my final year. For my final year project I am to design and simulate a shell and tube heat exchanger. the point of the capstone is to vary baffle angle and cut to increase heat transfer and reduce pressure drop. While running a parametric sweep i have encountered many errors. one of the errors is pasted below:

"""TA"",""0.34907"",""cut"",""0.4""" "Error in sweep.⏎ - Parameters: ""TA"",""0.34907"",""cut"",""0.4""⏎The following feature has encountered a problem:⏎ - Feature: Time-Dependent Solver 1 (sol1/t1)⏎Failed to find consistent initial values.⏎Temperature⏎Attempt to evaluate real square root of negative number.⏎Function: sqrt⏎Failed to evaluate operator.⏎Operator: nif, Geometry: geom1, Boundary: 30⏎Failed to evaluate expression.⏎Expression: nif(comp1.spf.d w plus u<(10/(up(comp1.nitf1.Pr)^0.33333333333333331483)),nojac(comp1.spf.d w plus uup(comp1.nitf1.Pr)),comp1.spf.d w plus u1000)/up(comp1.nitf1.Prt)),nojac((15(up(comp1.nitf1.Pr)^0.66666666666666662966))-(500/(comp1.spf.d w plus u^2))),nojac(((15(up(comp1.nitf1.Pr)^0.66666666666666662966))+((up(comp1.nitf1.Prt)log(comp1.spf.d w plus u))/comp1.spf.kappav))-(((0.5up(comp1.nitf1.Prt))(1+log((comp1.spf.kappav1000)/up(comp1.nitf1.Prt))))/comp1.spf.kappav)))⏎Failed to evaluate expression.⏎Expression: if(comp1.spf.hasWF u,nif(comp1.spf.d w plus u<(10/(up(comp1.nitf1.Pr)^0.33333333333333331483)),nojac(comp1.spf.d w plus uup(comp1.nitf1.Pr)),comp1.spf.d w plus u1000)/up(comp1.nitf1.Prt)),nojac((15(up(comp1.nitf1.Pr)^0.66666666666666662966))-(500/(comp1.spf.d w plus u^2))),nojac(((15(up(comp1.nitf1.Pr)^0.66666666666666662966))+((up(comp1.nitf1.Prt)log(comp1.spf.d w plus u))/comp1.spf.kappav))-(((0.5up(comp1.nitf1.Prt))(1+log((comp1.spf....1000)/up(comp1.nitf1.Prt))))/comp1.spf.kappav))),0)⏎Failed to evaluate variable.⏎Variable: comp1.nitf1.Tplus u, Defined as: if(comp1.spf.hasWF u,nif(comp1.spf.d w plus u<(10/(up(comp1.nitf1.Pr)^0.33333333333333331483)),nojac(comp1.spf.d w plus uup(comp1.nitf1.Pr)),comp1.spf.d w plus u1000)/up(comp1.nitf1.Prt)),nojac((15(up(comp1.nitf1.Pr)^0.66666666666666662966))-(500/(comp1.spf.d w plus u^2))),nojac(((15(up(comp1.nitf1.Pr)^0.66666666666666662966))+((up(comp1.nitf1.Prt)log(comp1.spf.d w plus u))/comp1.spf.kappav))-(((0.5up(comp1.nitf1.Prt))(1+log((comp1.spf.kappav1000)/up(comp1.nitf1.Prt))))/comp1.spf.kappav))),0)⏎Failed to evaluate expression.⏎Expression: if(comp1.spf.hasWF u,(((-comp1.nitf1.qwfc u)up(comp1.ht.Cp))(comp1.ht.Tu-comp1.nitf1.TuWF))/sqrt(1.0E-6+(max(comp1.nitf1.Tplus u,0)^2)),0)⏎Failed to evaluate variable.⏎Variable: comp1.nitf1.qwf u, Defined as: if(comp1.spf.hasWF u,(((-comp1.nitf1.qwfc u)up(comp1.ht.Cp))(comp1.ht.Tu-comp1.nitf1.TuWF))/sqrt(1.0E-6+(max(comp1.nitf1.Tplus u,0)^2)),0)⏎Failed to evaluate expression.⏎Expression: (-comp1.nitf1.qwf u)comp1.ht.d⏎Failed to evaluate Jacobian of expression.⏎Expression: ((-comp1.nitf1.qwf u)test(comp1.nitf1.TuWF-comp1.ht.Tu))comp1.ht.d⏎Failed to evaluate Jacobian of expression.⏎Expression: (if(comp1.spf.hasWF u,-comp1.nitf1.qwf utest(comp1.nitf1.TuWF-comp1.ht.Tu)comp1.ht.d,0))(dvol spatial)⏎Last time step is not converged."