Reynold’s Number is a descriptive property of a flow that can help determine how heat and mass is transported. It is the ratio of the inertial to viscous force in the fluid (i.e. how fast is the flow moving relative to how viscous it is). Specifically, it can predict if a flow is laminar (smooth with little to no intersection between flow lines) or turbulent (chaotic with a lot of mixing of flow lines). A flow will transition between laminar and turbulent when…
The Prandtl Number is an intrinsic property of a fluid that describes which mechanism dominates heat transfer. Specifically, it is the ratio of momentum diffusivity (how quickly energy is dispersed by convection) to thermal diffusivity (how quickly energy is dispersed as heat). In the abstract, the Prandtl Number describes how quickly a “velocity wave” moves relative to the speed of the “thermal wave” in the fluid. Here, Pr is the Prandtl Number, is the specific heat, is the dynamic viscosity,…
The continuity equation in fluid dynamics says that mass is conserved throughout a fluid (mass flux in = mass flux out). Because a fluid is a continuous medium, there are different frames of reference to observe it properties, and this will affect how the continuity equation is calculated. In the Eulerian frame of reference, we focus on a fixed region of interest and allow the fluid to flow in and out and observe its properties. The only way to change…
Ion Cyclotron Waves (ICWs) are transverse shear waves produced as energy is released from a higher energy anisotropic distribution of ions (a.k.a. a “ring distribution” in velocity space) to a lower energy isotropic distribution. Specifically, the anisotropy arises when neutrals are ionized and accelerated along the magnetic field. The ICWs will release energy from the plasma and scatter the pick-up ions’ velocity back to thermal equilibrium. Tpar describes the ions’ temperature distribution parallel to the magnetic field and Tperp describes…