Reynolds Transport Theorem

Taylor Emma
2 Min Read
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  Key Concept:  The Reynolds Transport Theorem provides a way to transfer equationsfor conservation of mass, momentum, and energy from the Lagrangian point of view to the Eulerian point of view using a control surface and a control volume.  In a Nutshell:  You can study fluid motion either by following fluid particles (system, the Lagrangianpoint of view) or by observing fluid flow past a control volume (finite volume, Eulerian point of view). Let  B  denote extensive property related to fluid flow such as mass, linear momentum, angularmomentum, or energy.  Let  b  denote  comparable intensive property such as mass per unit mass,linear momentum per unit mass, angular momentum per unit mass, or energy per unit mass.  Then Reynolds transport theorem is:                           DB/dt |sys =  ∂/∂t  ∫ ρb dV  +  ∫ ρb V . n dS                                               cv              cs                           cv = control volume,    cs  =  control surface where  B      =  the extensive property (contained in the system, fixed quantity)            b       =   the intensive property = property per unit mass            ρ       =   the mass density of the fluid        ∂/∂t      =    the time rate of change          dV      =    the element of volume within the control volume         V        =   the fluid velocity crossing the control surface         n         =    the unit outward normal to the control surface     V . n      =    the normal component of velocity crossing the control surface (dot product)       dS         =     the element of area on the control surface Physical Interpretation of Reynolds Transport Theorem DB/dt  represents the time rate of change of the arbitrary extensive property,  B ∂/∂t  ∫ ρb dV   represents the time rate of change of  B within the control volume
      cv  ∫ ρb V . n dS     represents the flux of  B  across the control surfacecs
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A senior editor for The Mars that left the company to join the team of SenseCentral as a news editor and content creator. An artist by nature who enjoys video games, guitars, action figures, cooking, painting, drawing and good music.
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