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Unexpected unit of input. :Function- exp

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I am trying to add an equatiom ii definition node under variable section. It turns yellow showing error message as: **Unexpected unit of input - Function: exp***

Why it is so? What is the mistake in input, can anyone tell? Screenshot attached for reference. Please help.



2 Replies Last Post Feb 20, 2019, 1:18 a.m. EST
Magnus Ringh COMSOL Employee

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Posted: 5 years ago Feb 19, 2019, 9:41 a.m. EST
Updated: 5 years ago Feb 20, 2019, 2:07 a.m. EST

Hi,

The exponential function exp expects a dimensionless input. I'm not sure what T is, but it might be a temperature, which makes the input to the function dimensionally inconsistent. If the numerator is a temperature, enter it as 9459[K], or else you can "dedimensionalize" the denominator as, for example, T[1/K].

Best regards, Magnus Ringh, COMSOL

Hi, The exponential function `exp` expects a dimensionless input. I'm not sure what `T` is, but it might be a temperature, which makes the input to the function dimensionally inconsistent. If the numerator is a temperature, enter it as `9459[K]`, or else you can "dedimensionalize" the denominator as, for example, `T[1/K]`. Best regards, Magnus Ringh, COMSOL

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Posted: 5 years ago Feb 20, 2019, 1:18 a.m. EST

Yes, T is temperature. Thanks this worked. This equation is antonie equation. Is there any unit for these constant a, b in antonie eqn to make this equation dimensionally consisitent? as these equation solves for pressure.

Yes, T is temperature. Thanks this worked. This equation is antonie equation. Is there any unit for these constant a, b in antonie eqn to make this equation dimensionally consisitent? as these equation solves for pressure.

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