A coupled model of transport, turbulence, and mesoscale flows is proposed, including turbulence spreading. The model consists of transport equations for plasma density and pressure coupled to a shell model of drift wave turbulence, which incorporates coupling to mesoscale flows via disparate scale interactions. The model can describe the turbulent cascade and its dynamical interplay with zonal and mean shear flows as well as the profile evolution (including the profiles of turbulence intensity itself) due to these self-consistent turbulent fluxes. This simple system of equations is shown to capture the low to high confinement (L-H) transition. It is also observed that as the heating is increased, the system goes through an intermediate …show more content…
For instance the models including the effect of evolution of plasma turbulence driven by profile gradients were proposed and studied by various authors (see, e.g., Refs. 7 and 18). In particular, the model of Miki et al.7,19,20 has the advantage of including oscillations between two predators (zonal flows and mean flows) and one prey (turbulence) while achieving the L-H transition. As such, it is also able to describe an L-I-H transition (L-H transition with an intermediate phase), which was initially predicted by a 0D model.21,22 However in most of the reduced models, the transport coefficients are determined by an ad hoc shear suppression rule. Here we propose an approach based on shell models, where the shear suppression and the predator-prey dynamics are natural results of the disparate scale interactions incorporated within the shell model description. The model that is introduced in this paper is interesting for various reasons. It is significant, for instance, in that it makes use of a simple description of turbulence based on shell models, yet it is able to describe the complex interplay between turbulence and zonal flows in a natural self-consistent way, without making use of ad hoc steady-state relations such as the shear suppression rule. On the other hand, the model
\KwIn{nodal value of solution $\mathbf{u} = \left(p, \mathbf{v} \right)$, volume geometric factors $\partial (rst)/ \partial (xyz)$, 1D derivative operator $D_{ij} = \partial \hat{l}_j /\partial x_i$, model parameters $\rho, c$}
As a result of the experiment and computation of data, the aerofoil was found to have a critical Mach number of M=0.732. Below this freestream Mach number the Prandtl-Glauert law predicted results very
Assuming no viscous forces present an inviscid model has been used for the calculations. Also from the equation of the Reynolds number Re=ρvl/μ due to Re being really big rearranging and assuming v and l to be constant the viscous force μ =ρvl/Re becomes negligible.
Weather is created by the movement of air masses of different temperature and moisture content moving around the Earth’s atmosphere and interacting with each other.
As storm relative velocity helps analyze the motion of the winds within the storm, information like the rotation of the storm and the speed of the winds can help investigate the chances of the storm developing into a tornado. If the storm appears to be a threat, nearby communities can be notified to take precautions and leave if necessary. Although base velocity can be used for the same reason, the speed of the storm can affect the results of the speed and rotation of winds. Therefore, storm relative velocity is more accurate and reliable than base velocity in determining the threat of a
The benefits of running convection-allowing models (CAMs) for convective storm prediction have been demonstrated in a variety of contexts over the past decade (e.g., Done et al. 2004; Kain et al. 2006; Lean et al. 2008; Kain et al. 2008; Clark et al. 2009; Coniglio et al. 2010; Schwartz et al. 2009; Sobash et al. 2011; Clark et al. 2010, Clark et al. 2011; Weisman et al. 2013). As these studies show, much of the value of running CAM forecasts comes from their ability to provide explicit information about convective properties such as initiation, mode, motion, longevity, and intensity. To effectively use CAM output in operational forecasting settings, novel forms of guidance are needed to summarize these forecast attributes in ways that can be easily understood by forecasters and other end users.
Potential connections exist between total lightning and mesovortex formation, which is the parent circulation from which QLCS tornadoes are born. Many studies have found that mesovortexgenesis is initiated at low levels by tilting, in downdrafts, of crosswise baroclinic horizontal vorticity (Trapp and Weisman 2003 Part II, Wheatley and Trapp 2008, Atkins and St. Laurent 2009 Part II). Additional studies have found that strong low-level updraft is critical in converging and amplifying vertical vorticity associated with the mesovortex (Schenkman et al. 2012, Atkins and St. Laurent 2009). Trapp and Weisman (2003 Part I) also found that the amount of wind shear had large implications on mesovortexgenesis. As wind shear increased in both magnitude and
Weisman and Trapp (2003 Part I) found that “contributions from dynamic forcing for the bow-echo updraft are much weaker and maximized near the surface, reflecting the strong convergence and rotation at the leading edge of the cold pool as opposed to forcing from a midlevel mesocyclone”. Strong negative dynamic forcing also helps explain the relatively shallower and more tilted structure of the QLCS mesovortex compared to that of a supercell mesocyclone. Tornadoes associated with QLCSs differ in many ways from supercells. They form in different convective environments, take on completely different appearances on radar (Figure 2.3) and have different microphysical and dynamical processes. QLCS tornadoes are not spawned from mesocyclones and do not typically produce a descending velocity signature on radar signifying a descending mesocyclone, which is an important precursor for supercell tornadoes.
The primary process responsible for cooling the sea surface under a hurricane is vertical mixing. Vertical mixing occurs because the hurricane’s surface winds exert a stress on the ocean surface due to friction, generating ocean currents in the oceanic mixed layer. Vertical shear of the currents in the upper ocean then leads to turbulence. If so how and with what can it be predicted with? Hurricane can be predictable but it do not admit the possibility of being timely anticipated beyond about four days but it is known that the tool to establish analytically the fundamental features of a hurricane such as the intensity of the winds also using dynamic maps in which it is possible to identify scales, Temperatures and intensities of the wind gusts.
The liquid mosaic model depicts the plasma layer of
Base on my marriage of six-years, my previous marriage and witnessing how my close friends interact in their relationships, I can conclude that I agree and relate to most of the author’s description on Social Exchange Theory. Just like explained in the comparison level, we all believe that we have outcomes that we are entitled to in any relationship we have. (Miller, 2015, p. 177) For example, in my friendships, if I put ‘X’ amount of effort in a friendship, I expect my friend to put the at least the equal amount of effort. I would not consider my happy and successful six-year marriage to have had costs. We have invested so much into our relationship though. Maybe I feel this way due to the fact that I know my wife and I are such a great fit
Predicting tornado activity can be one of the most challenging aspects of Meteorology. Tornados can form in less than 10 seconds, providing little to no warning of the potential devastating destruction they leave behind. With advancements in technology being more aware of the formation of tornados would appear to be a natural outcome. Research indicates, that the advancement in predicting tornados is closely related to understanding better why early predictions are challenging.
Outside, cool dry, seeking air starts to rap around the back of the mesocyclone, known as a Rear Flank Downdraft. The Rear Flank Downdrafts creates a start temperature difference between the outside and inside temperature of the mesocyclone. Building the instability for a tornado to thrive. Then the mesocyclone’s lower part becomes tighter, increasing the speed of the wind. If the funnel of air moves down into the large moist cloud base at the bottom of the parent storm, it sucks it in and turns it into a rotating wall of cloud. Forming a link between the storm that is created and the earth, as known as the touch down phase. The second the spinning cloud touches the ground; it becomes a tornado. Producing winds of 65 to 110 miles/hour or 104 to 177 km/hour with 200 mph winds. A tornado can last up 5 minutes or for multiple hours. The distance the tornado covers depends on the rate at which the RFD cools. If the RFD cannot further provide any more air to the tornado, it begins to die. Warm air decreases, the vortex begins to weaken and shrivel
(-- removed HTML --) The stellarator TJ-K (-- removed HTML --) (-- removed HTML --) 17 (-- removed HTML --) (-- removed HTML --) provides a well suited environment to test experimentally for scalings of turbulence with control parameters such
They have also determined how the Gardner solution differs from the KdV and mKdV solutions based on the typical data of Refs. (-- removed HTML --) 19 (-- removed HTML --) , (-- removed HTML --) 40 (-- removed HTML --) , and (-- removed HTML --) 41 (-- removed HTML --) , and mentioned that these plasmas may exist in various cosmic dust-laden plasmas, (-- removed HTML --) (-- removed HTML --) 42,43 (-- removed HTML --) (-- removed HTML --) where two distinct temperature ions (-- removed HTML --) (-- removed HTML --) 41,44,45 (-- removed HTML --) (-- removed HTML --) can significantly modify the wave dynamics. However, the role of the head-on collisions between the DA waves may not be ignored, because it plays an important role in understanding physical scenarios of plasmas. Being motivated by the potentiality of the problems related to the astrophysical, space, and laboratory plasmas, the head-on collisions among the DA single- and multi-solitons and their phase shifts in unmagnetized plasmas consisting of massive negatively charged mobile dust particles, Boltzmann distributed electrons, and two-temperature nonthermal ions are investigated; the two-temperature nonthermal cold and hot ions occupy two different regions of phase space. The effects of cold and hot ions temperature ratio ( (-- removed HTML --)