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comsol3.4 code doesn;t run on comsol 3.5a

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Hello Everyone,

Kindly share your experience if you encountered similar problem.

I am using Comsol 3.5 with matlab and the following error is displayed while the same code works fine with Comsol 3.4. The problem is 2D- trasient with Navier-Stokes module.

Thanks,
Mranal



??? Java exception occurred:
Exception:
com.femlab.jni.FlNativeException: Failed to evaluate expression
Messages:
Failed to evaluate expression
- Expression:
d(d((((-2*eta_ns*ux+p)*test(ux)-eta_ns*(uy+vx)*test(uy)+gls_ns+shock_capt_ns)-(0))*(dvol_ale),{test@4}),xxi2)

Failed to evaluate symbolic derivative variable
- Variable: shock_capt_ns@VDN${test@4}@VDN$xxi2
- Defined as:
((((d(y,xi2))*uy)+(ux*((2*d(x,xi2)))))*((-nojac((min((gijgij_ns^-0.25),((U_ale_ns*rho_ns)/(48*eta_ns)))*(0.5*min((sqrt((((taum_ns*res_v_ns)^2)+((((tauc_ns*res_p_ns)/(nojac(sqrt((u2int_g1_ns/vol_g1_ns)))*nojac((rhoint_g1_ns/vol_g1_ns)))))^2+((taum_ns*res_u_ns))^2)))*ck_ns),U_ale_ns)))))*rho_ns))

Failed to evaluate expression
- Expression:
nojac((min((gijgij_ns^-0.25),((U_ale_ns*rho_ns)/(48*eta_ns)))*(0.5*min((sqrt((((taum_ns*res_v_ns)^2)+((((tauc_ns*res_p_ns)/(nojac(sqrt((u2int_g1_ns/vol_g1_ns)))*nojac((rhoint_g1_ns/vol_g1_ns)))))^2+((taum_ns*res_u_ns))^2)))*ck_ns),U_ale_ns))))

Sqrt of negative
- Function: sqrt

Stack trace:
at evaltree.cpp, row 866, ()
at evalnodes.cpp, row 1083, ()
at xevalutil.cpp, row 2659, ()
at evalfun_basic.cpp, row 237, ()
at com.femlab.solver.FlSolver.femTime(Native Method)
at com.femlab.solver.FemTime.run(Unknown Source)
at com.femlab.server.FlRunner.run(Unknown Source)
at com.femlab.server.q.run(Unknown Source)
at com.femlab.util.i.run(Unknown Source)
at com.femlab.util.aa.run(Unknown Source)

Error in ==> femsolver at 368
solobj.smartRunner(report, loopTime);

Error in ==> femtime at 120
varargout = femsolver(mfilename,'FemTime',varargin{:});

Error in ==> EK_sphere_particle_ALE_Rpt1 at 272
fem.sol=femtime(fem, ...

1 Reply Last Post 2009年9月4日 GMT-4 05:31

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Posted: 1 decade ago 2009年9月4日 GMT-4 05:31
The improved crosswind stabilization in version 3.5a can get singular if you for example by mistake set rho=0. A common pitfall is to compute rho(p,T) by the ideal gas (say) and you set p instead of p+1[atm] as argument, while at the same time having p=0 at an outlet.

A suggestion is to check the model for this and other possible divergence reasons.

Niklas Rom
COMSOL
The improved crosswind stabilization in version 3.5a can get singular if you for example by mistake set rho=0. A common pitfall is to compute rho(p,T) by the ideal gas (say) and you set p instead of p+1[atm] as argument, while at the same time having p=0 at an outlet. A suggestion is to check the model for this and other possible divergence reasons. Niklas Rom COMSOL

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