by Chris Peterson » Sat Jan 22, 2011 5:36 pm
dougettinger wrote:These few questions may be outside your realm of knowledge, Chris. I do not know how accessible the input data is for computer modeling of protostar or solar system genesis. For fluid dynamic considerations is Bernoilli's Equation, Euler's Equations or the Navier-Stokes Equations utilized ? Are the protostar disk materials for this modeling considered to be viscous or inviscid flows ? Compressible or incompressible flows ? Turbulent or laminar flows ? Electrically conducting flows ? Does the computer modeling use equations for gravity, fluid dynamics, thermodynamics, electromagnatic forces, and radiative forces simultaneously ?
I don't know the specifics of the modeling used. I do know something about this sort of modeling in general, and it probably applies here. Models can have physical components and they can have empirical components. Everybody likes physical components and prefers avoiding the empirical (but this isn't always possible). You would expect a model that includes fluid dynamics to utilize all the available physical theory, which includes the equations you mention. The other stuff you bring up- viscous vs nonviscous, laminar vs turbulent, etc will be outputs of the model, not inputs or something to be considered.
And yes, AFAIK stellar system models consider all the factors you list. Fluid dynamics is just one process. The model won't be accurate without including all the physical processes presumed to be factors. Models generally improve in three ways: the physics get better, and the number of factors solved for increase, and the resolution (time and space) improve.
[quote="dougettinger"]These few questions may be outside your realm of knowledge, Chris. I do not know how accessible the input data is for computer modeling of protostar or solar system genesis. For fluid dynamic considerations is Bernoilli's Equation, Euler's Equations or the Navier-Stokes Equations utilized ? Are the protostar disk materials for this modeling considered to be viscous or inviscid flows ? Compressible or incompressible flows ? Turbulent or laminar flows ? Electrically conducting flows ? Does the computer modeling use equations for gravity, fluid dynamics, thermodynamics, electromagnatic forces, and radiative forces simultaneously ?[/quote]
I don't know the specifics of the modeling used. I do know something about this sort of modeling in general, and it probably applies here. Models can have physical components and they can have empirical components. Everybody likes physical components and prefers avoiding the empirical (but this isn't always possible). You would expect a model that includes fluid dynamics to utilize all the available physical theory, which includes the equations you mention. The other stuff you bring up- viscous vs nonviscous, laminar vs turbulent, etc will be outputs of the model, not inputs or something to be considered.
And yes, AFAIK stellar system models consider all the factors you list. Fluid dynamics is just one process. The model won't be accurate without including all the physical processes presumed to be factors. Models generally improve in three ways: the physics get better, and the number of factors solved for increase, and the resolution (time and space) improve.