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Using conservation of mass, energy and momentum to calculate vapor expansion

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Hi every one,

I am trying to develop a model describing the vapour expansion process in vacuum (or background gas), based on the conservation of mass, energy and momentum. The distributions of density, velocity and energy at different time moment are expected. I chose the Coefficient Form PDE of Mathematics, and solve the three equations simultaneously. I found some problem in 1D condition; sometimes it can get a result, sometime it cannot. For the results obtained (distribution of density, velocity and energy), there is some oscillation in the simulation result, which is unphysical since the density may be negative. And the 2D model cannot proceed successfully.

I post the 1D model. Can anyone please give me some suggestion about this model? How to improve it, or other way to describe this process more conveniently?

Thanks
Hao


1 Reply Last Post 10 avr. 2016, 03:46 UTC−4
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Hello Hao Zhu

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Posted: 9 years ago 10 avr. 2016, 03:46 UTC−4
Hi

even I am trying to solve conservation eqns and Im getting oscillations at boundaries. What are your boundary and initial conditions?

did u get a solution for the same?
Hi even I am trying to solve conservation eqns and Im getting oscillations at boundaries. What are your boundary and initial conditions? did u get a solution for the same?

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