Modelling Air Resistance using Differential Equation

AI Thread Summary
The discussion focuses on modeling air resistance using differential equations for a project. Key assumptions include the consistency of air resistance without pressure changes and the absence of drafts in the experimental setup. Participants highlight the importance of selecting the appropriate type of friction force, such as Stokes type for small velocities or drag forces for larger velocities. The Reynold's Number is emphasized as a crucial factor in determining the turbulence regime and drag characteristics, which influence the modeling approach. Overall, understanding these parameters is essential for accurately formulating the differential equations related to air resistance.
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hi ,

As a part of my project, i am modelling air resistance using a differential equation. For the write up, i need to discuss what assumptions i am making. I have the rest of the coursework sorted out.

I have a few idea .

Air resistance is presumed to be consistent. ( i.e no pressure changes)
There are no drafts or breezes in the experimental setup.

Any others?

sid
 
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well i have posted some of ideas already but i was wondering what would be the main sources of errors and assumptions of dropping some paper cups to measure air resistance constant.
 
You wish to set up a diff.equation.That's okay.There are 2 types of friction forces involved:Stokes type (viscous fluid,small velocities) and drag forces (big velocities)...

So choose the exact type of model (gravity,velocity range) and then set up the diff.eq.

Daniel.
 
$id said:
hi ,

As a part of my project, i am modelling air resistance using a differential equation. For the write up, i need to discuss what assumptions i am making. I have the rest of the coursework sorted out.
"Air Resistance" (or "Aerodynamic Drag") has been studied extensively. There are several different physical phenomena involved, and the dominant factors are generally indicated by the Reynold's Number value(s) for the experiment. Reynold's Number usually provides indication of the turbulence regime and drag characteristics, and thus the general approaches you can take in studying your problem. Parameters like Drag Coefficient are usually involved in formulating the basic equations. The URLs below discuss these concepts and should help formulate your approach. (Most involve a series of tutorial pages.)
http://www.lerc.nasa.gov/WWW/K-12/airplane/falling.html
http://www.eng.auburn.edu/department/me/courses/nmadsen/egr182a/drag01.html
http://galileo.phys.virginia.edu/classes/311/notes/fluids2/node8.html
http://astron.berkeley.edu/~jrg/ay202/node21.html



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