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How to get time when Temperaure reached at a value?

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Hello!

I'd like to store time value to local variable during solution. Could you show me about how to get time value when dependent variable(Temperature, etc. reached at a certain value?


1 Reply Last Post 21.03.2018, 07:46 GMT-4
Magnus Ringh COMSOL Employee

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Posted: 6 years ago 21.03.2018, 07:46 GMT-4

Hi,

One way to get a value for when a dependent variable (or rather, some aspect of it, such as the mean temperature or temperature in a point, since the dependent variable typically is a field) is to add a stop condition to the time-dependent solver. The stop condition will stop the time stepping when the condition is fulfilled (for example, that the threshold temperature minus the temperature in a point becomes negative).

Another way, if you want a variable that you can plot and evaluate, could be to define an ODE, perhaps using a Point ODEs and DAEs interface at a point of interest in the geometry. Then integrate the ODE variable with a source term that is a Boolean variable that is 1 initially and becomes 0 when the temperature reaches a certain value (such as T_inpoint<400[K], where T_inpoint represents the temperature in that point. The value of the ODE variable is then equal to time, up unitl the temperture reaches 400 kelvin; the value then stays at the time when the temperature reached 400 K.

Best regards, Magnus Ringh, COMSOL

Hi, One way to get a value for when a dependent variable (or rather, some aspect of it, such as the mean temperature or temperature in a point, since the dependent variable typically is a field) is to add a stop condition to the time-dependent solver. The stop condition will stop the time stepping when the condition is fulfilled (for example, that the threshold temperature minus the temperature in a point becomes negative). Another way, if you want a variable that you can plot and evaluate, could be to define an ODE, perhaps using a Point ODEs and DAEs interface at a point of interest in the geometry. Then integrate the ODE variable with a source term that is a Boolean variable that is 1 initially and becomes 0 when the temperature reaches a certain value (such as `T_inpoint

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