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Error: Attempt to evaluate negative power of zero.

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Hi,

I'm faced with this error when solving my time-dependent problem:

Attempt to evaluate negative power of zero.
- Function: ^
Failed to evaluate temporary symbolic derivative variable.
- Variable: Ve_r@VDN${abs@5}
- Defined as: ((sign(mod1.es.Er)*(-60.600000000000001))*(0.75*(abs((0.01*mod1.es.Er))^(-0.25))))
Failed to evaluate temporary symbolic derivative variable.
- Variable: mod1.cd2.u@VDN${abs@5}
- Defined as: (((sign(mod1.es.Er)*(-60.600000000000001))*(0.75*(abs((0.01*mod1.es.Er))^(-0.25)))))
Failed to evaluate expression.
- Expression: d(mod1.cd2.u,{abs@5})
Failed to evaluate operator Jacobian.
- Operator: mean

Can anyone help?

Thanks

1 Reply Last Post 27 set 2016, 05:47 GMT-4
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Hello Imran Ibrahim

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Posted: 8 years ago 27 set 2016, 05:47 GMT-4
Hi...
i try to module the electricall double layer, using electrostatic et transport of diluted species module but I cannot successfully implement the surface charge in boundary condition and i had the same problem and it seem the same msg error :


Attempt to evaluate negative power of zero.
- Function: ^
Failed to evaluate temporary symbolic derivative variable.
- Variable: comp1.Surf_Charge_Density@VDN$comp1.phi
- Defined as: (((comp1.CONST7^(-0.5))*0.5)*((-((-(((((exp((-comp1.phi)/V_therm)*(-(1/V_therm)))*cA_bulk)*CONST1)*a3)*comp1.CONST3))*(1/(1-(comp1.CONST3*(a3*comp1.NS_positif))))))*CONST2))*e_const
Failed to evaluate temporary symbolic derivative variable.
- Variable: comp1.es.sfcd1.rhoqs@VDN$comp1.phi
- Defined as: (((comp1.CONST7^(-0.5))*0.5)*((-((-(((((exp((-comp1.phi)/V_therm)*(-(1/V_therm)))*cA_bulk)*CONST1)*a3)*comp1.CONST3))*(1/(1-(comp1.CONST3*(a3*comp1.NS_positif))))))*CONST2))*e_const
Failed to evaluate expression.
- Expression: ((-((((comp1.CONST7^(-0.5))*0.5)*((-((-(((((exp((-comp1.phi)/V_therm)*(-(1/V_therm)))*cA_bulk)*CONST1)*a3)*comp1.CONST3))*(1/(1-(comp1.CONST3*(a3*comp1.NS_positif))))))*CONST2))*e_const))*comp1.es.d)*dvol
Failed to evaluate Jacobian of expression.
- Expression: (comp1.es.d*(-comp1.es.sfcd1.rhoqs))*dvol
Failed to evaluate Jacobian of expression.
- Expression: (-comp1.es.sfcd1.rhoqs*test(comp1.phi)*comp1.es.d)*(dvol)
- Feature: Stationary Solver 1 (sol3/s1)


so please did you find a solution and how can i fix it
Appreciate much for your help!!
Hi... i try to module the electricall double layer, using electrostatic et transport of diluted species module but I cannot successfully implement the surface charge in boundary condition and i had the same problem and it seem the same msg error : Attempt to evaluate negative power of zero. - Function: ^ Failed to evaluate temporary symbolic derivative variable. - Variable: comp1.Surf_Charge_Density@VDN$comp1.phi - Defined as: (((comp1.CONST7^(-0.5))*0.5)*((-((-(((((exp((-comp1.phi)/V_therm)*(-(1/V_therm)))*cA_bulk)*CONST1)*a3)*comp1.CONST3))*(1/(1-(comp1.CONST3*(a3*comp1.NS_positif))))))*CONST2))*e_const Failed to evaluate temporary symbolic derivative variable. - Variable: comp1.es.sfcd1.rhoqs@VDN$comp1.phi - Defined as: (((comp1.CONST7^(-0.5))*0.5)*((-((-(((((exp((-comp1.phi)/V_therm)*(-(1/V_therm)))*cA_bulk)*CONST1)*a3)*comp1.CONST3))*(1/(1-(comp1.CONST3*(a3*comp1.NS_positif))))))*CONST2))*e_const Failed to evaluate expression. - Expression: ((-((((comp1.CONST7^(-0.5))*0.5)*((-((-(((((exp((-comp1.phi)/V_therm)*(-(1/V_therm)))*cA_bulk)*CONST1)*a3)*comp1.CONST3))*(1/(1-(comp1.CONST3*(a3*comp1.NS_positif))))))*CONST2))*e_const))*comp1.es.d)*dvol Failed to evaluate Jacobian of expression. - Expression: (comp1.es.d*(-comp1.es.sfcd1.rhoqs))*dvol Failed to evaluate Jacobian of expression. - Expression: (-comp1.es.sfcd1.rhoqs*test(comp1.phi)*comp1.es.d)*(dvol) - Feature: Stationary Solver 1 (sol3/s1) so please did you find a solution and how can i fix it Appreciate much for your help!!

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