Coupling of Wind and Potential Temperature in an Ekman Model in the Stratified Atmospheric Boundary Layer

A linear Ekman model in the stratified atmospheric boundary layer (ABL) is proposed based on the steady state version of the linearized three-dimensional primitive equations with the inclusion of the vertical diffusivity. Due to the inclusion of the potential temperature equation and hydrostatic equation, pressure and potential temperature couple with wind in the proposed model, and thus are not arbitrarily specified variables as in previous studies on the baroclinicity in the Ekman model. The extended thermal wind balance equation and the Ekman potential vorticity equation are derived to describe the coupling. The two equations, along with the equation describing the constraint on potential temperature, are employed to derive the analytical solutions of the proposed Ekman model. Because potential temperature is not a specified variable but part of the solution, the derived analytical solutions have very different forms from those derived in previous studies. The differences illustrate the impact of the inclusion of the potential temperature equation and hydrostatic equation on wind, pressure and potential temperature in the proposed Ekman model. It is found that the computed wind profiles based on the proposed model can capture some important features of the observed wind profiles.

Estimation of Evapotranspiration and Water Requirements of Strawberry Plants in Greenhouses Using Environmental Data

Farmers routinely determine irrigation requirements from visual observations and cultivation experience, but this can lead to under- or over-irrigation. To establish precise irrigation technology for strawberry cultivation, the average daily evapotranspiration and water requirements were estimated according to the environmental data: air temperature and humidity from the center of the greenhouses and solar radiation from outside greenhouses. Makkink FAO24 equations (temperature and cloudiness) were used to estimate the evapotranspiration and water requirements. The temperature equation showed higher correlation coefficients in solar radiation (R2 = 0.60), evapotranspiration (R2 = 0.76), and water requirements (R2 = 0.69) than other tested equations. The daily irrigation, calculated from the estimated evapotranspiration, was 3.8 tons/10a. It is possible to develop a precision irrigation system from estimated evapotranspiration during the winter cultivation of “Seolhyang” strawberries in South Korea.

Algorithm for calculating parameters of mold temperature controller

This paper presents a method to calculate the parameters of mold temperature controller based on the fast algorithm of mold water heating with these problems that it is difficult to calculate the parameters of injection mold temperature controller and it can’t be simulated. According to the requirements of fast mold water heating algorithm, firstly, similar transformations are used to construct a similar model to obtain a similar model with the same solution of the fluid-solid coupling mathematical model of mold water heating. The temperature field of the mold after heating is obtained through rapid simulation of the similar model. Secondly, a constrained mold temperature control equation is established, and the iterative method is used to numerically solve the mold temperature equation to obtain the mold temperature controller parameters that meet the heating conditions. An example is given in this paper to show that the calculation method of mold temperature controller parameters presented in this paper has good practical value.

A regularity criterion for a 2D tropical climate model with fractional dissipation

Tropical climate model derived by Frierson et al. (Commun Math Sci 2:591–626, 2004) and its modified versions have been investigated in a number of papers [see, e.g., Li and Titi (Discrete Contin Dyn Syst Series A 36(8):4495–4516, 2016), Wan (J Math Phys 57(2):021507, 2016), Ye (J Math Anal Appl 446:307–321, 2017) and more recently Dong et al. (Discrete Contin Dyn Syst Ser B 24(1):211–229, 2019)]. Here, we deal with the 2D tropical climate model with fractional dissipative terms in the equation of the barotropic mode u and in the equation of the first baroclinic mode v of the velocity, but without diffusion in the temperature equation, and we establish a regularity criterion for this system.

Use of the Speed of Sound for Heights Below the Troposphere in Colombia to Determine the Distance of Lightning Strikes

Objective: This paper aims to conduct a study of the speed of sound in Colombia for heights below the troposphere, taking into account the temperature as a function of altitude for a tropical zone, in order to determine the distance of lightning strike. Methodology: A speed of sound profile for Colombia was determined by analyzing data on altitude, temperature, and relative humidity in the country. The temperature equation as a function of altitude presented by NASA and the International Standard Atmosphere was taken into account to compare with the data obtained from meteorological stations located in different parts of the country (this stations measure information of temperature and other physical variables). Additionally, a sound profile map of Colombia was obtained using the interpolation in ArcGIS software. Results: A map of the speed of sound in Colombia was obtained, thus finding the speed range in the country. Likewise, the temperature was determined as function of the altitude for Colombia (a country in the tropical zone), with which it is possible to have data closer to the real speed of sound in the place and determinate the distance of impact of a lighting in land. Conclusions: The study of variables such as temperature, relative humidity, and altitude helped determine the speed of sound for Colombia. It was also possible to define a temperature equation as a function of altitude for a tropical country; with the speed of sound, the radius of impact of a lightning can be found.

Annulus shape tank with convective flow in a porous zone with impose of MHD

Current investigation deals with influence of inclusion of nanoparticles within the permeable medium within a tank with circular outer wall. The inner surface is hot and the radiative term has been imposed in temperature equation. Vorticity formula helps us to remove the pressure terms from equations and CVFEM was incorporated to calculate the amount of scalars in each node. With correlating the current data from previous paper, verification procedure was done which demonstrates good accuracy. Permeability has crucial role and greater values of Da results in stronger thermal penetration and isotherms become more disturbed. Intensity of cell augments with rise of Da about 70% in absence of Ha. Impose of Rd cannot affect the isotherms too much while it can change the Nu regarding the definition of this factor. When [Formula: see text], growth of Ha can decline the strength of eddy about 35%. Given [Formula: see text], as Da increases, Nu enhances about 10.24% and 0.25% when [Formula: see text]e5 and 1e3, respectively. Replacing platelet with sphere shape can augment the Nu about 0.38% and 0.6% when [Formula: see text] and 0, respectively.

A numerical investigation on the heat flow in the process of oil-water displacement in SDPSO

Spar Drilling Production Storage and Offloading (SDPSO) is a new type of deep ocean platform developed in recent years. The process of oil-water displacement is used for oil storage and offloading and the research on the accompanying heat flow has been significant. The wax precipitation and solidification at low temperature will particularly affect the flowing of oil in the displacement process. When the heat flow is concerned, numerical simulation requires large computation. It is necessary to develop an efficient numerical method for this calculation. As a kind of interface tracking method, the volume of fluid (VOF) method needs less computing resources compared with other multiphase numerical methods. As for thermal expressions, there are mainly two kinds of governing equations, i.e. temperature equation and enthalpy equation, and two kinds of interpolation scheme of heat conductivity, i.e. algebraic interpolation scheme and harmonic interpolation scheme. There is a need to find out which combination of governing equation and interpolation scheme of heat conductivity would result in a better precision for the heat flow. Therefore, four non-isothermal solvers, corresponding to the four combinations, are established. After comparison with an analytical solution, it is found that the temperature equation together with the harmonic interpolation scheme of heat conductivity results in better precision.