Changes between Version 1 and Version 2 of HydroStaticStar


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Timestamp:
10/16/12 13:51:00 (12 years ago)
Author:
idilernia
Comment:

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  • HydroStaticStar

    v1 v2  
     1= !HydroStatic Star =
     2
     3== Purpose ==
     4
     5This module aims to reproduce a situation of hydrostatic equilibrium (HSE), a condition where a volume of a fluid is at rest or at constant velocity. This occurs when compression due to gravity is balanced by a pressure gradient force.
     6
     7[[Image(Hydrostatic_equilibrium2.png, 250px)]]
     8
     9we can translate the image above into the condition:
     10
    111{{{
    212#!latex
    3 \frac{dP}{dh} = - \rho(h)\cdot g(h) \\
     13\frac{dP}{dh} + \rho \cdot g = 0\\
    414}}}
     15
     16= Implementation =
     17
     18Two fundamental objects are used by this module:
     19- [wiki:AmbientObjects Ambients]
     20- [wiki:Profiles Profiles]
     21- PointGravity
     22
     23For this module, the first step to recreate the solution is to determine a 1D profile in hydrostatic equilibrium, this profile can then be applied to a spherically symmetric 3D model using interpolation. [[BR]][[BR]]
     24With a little bit of imagination we can think of a 1D column of gas as an array of values:
     25
     26||COLUMN TOP||
     27
     28||h,,5,,||ρ,,5,,||P,,5,,||
     29||h,,4,,||ρ,,4,,||P,,4,,||
     30||h,,3,,||ρ,,3,,||P,,3,,||
     31||h,,2,,||ρ,,2,,||P,,2,,||
     32||h,,1,,||ρ,,1,,||P,,1,,||
     33||h,,0,,||ρ,,0,,||P,,0,,||
     34
     35||COLUMN BASE||
     36
     37We can relate each level of the column to an position in an array which contains height (h), density(ρ) and pressure(P).