Artificial drying of rough rice products is one of the most common methods of preservation. Rapid drying can increase brittleness and induce internal cracks which predispose the product to breakage during subsequent activities. The drying process must be designed and controlled so that design guidelines which reduce or minimize drying damage to rough rice products can be established and improved. This requires an accurate description of the drying mechanism. A finite element formulation and solution of a set of linear and nonlinear coupled conductive HEAT and diffusive moisture transfer equations to improve grain drying simulation of axisymmetric bodies is presented. Axisymmetric linear triangular elements with two degree of freedom per node are used to discretize the rice grain in both models. One medium grain, 'Cepidrod', was used. During the thin layer drying, temperature was measured every five second. Relative deviations of predicted values for linear and nonlinear models from measured data were calculated. The deviation obtained for nonlinear model was less than the linear model. Nonlinear model was improved by changing coefficient of LATENT HEAT of evaporation specific HEAT equation. The simulated temperature profile and gradient are directly usable for stress cracking analyses of rough rice. The results of the finite element analysis can be used for rough rice quality evaluation and drying simulation studies.      

A numerical model was developed to simulate the 3-D solidification of A319 aluminum alloy in a sand mold. The energy equation governing the process was derived based on total enthalpy conservation within the system. A source-based method was used to consider the release of LATENT HEAT during solidification. The governing energy equation was dicretized for a three-dimensional domain using a control volume based finite difference. The discretized equations associated with proper boundary conditions were solved numerically using TDMA (Tri Diagonal Matrix) algorithm. The model developed in this work, was verified by experimental results obtained from thermal analysis tests carried out on the casting. In order to evaluate the effect of LATENT HEAT release mode within the mushy region on temperature field and solidification profile in the casting, four modes were tested. These are linearly released mode, parabolic mode, and LATENT HEAT release modes based on lever rule and Scheil equation. A comparison of the computed results with the experiments showed that by incorporating the latter mode of LATENT HEAT release in the model, the solidification behavior of the casting can be predicted more accurately.

Thermal energy storing technologies are a new approach in reducing energy costs, managing demand side, pick shaving and increasing portion of renewable energies in energy production. In spite of the many advantages of thermal energy storage techniques, there are still major challenges in the path of LATENT HEAT thermal storage (LHTS). One of the challenges is the low charge and discharge rate of HEAT transfer in LHTS. In the current study charging rate of a shell and tube LHTS is numerically studied by enthalpy-porosity numerical technique. Exact positioning of the HEAT transfer tubes and thermal fins has great impact on the natural convection flows. In this study effect of increasing HEAT transfer tubes (HTF), lower positioning of tubes in four tubes configuration, changing upper tubes distance and using interconnected axial fins have been studied and compared to each other. Moreover, velocity and temperature contours have been analyzed. Results demonstrated that increasing number of tubes could not solve the slowing rate of charging at the end of process and tubes need to be positioned lower in the tube. In addition, it was observed that HEAT transfer axial fins can decelerate convection flows and develop stationary areas inside the shell. Prediction results revealed that, by lowering tubes and closing them to the shell wall, introduced in this article, it is possible to decrease charging time of 0.95 of storage capacity to one fourth of similar time in a one tube LHTS.

Spatial analysis of Iran's climate change from the point of view of sensible HEAT flux and LATENT HEAT flux by Bowen method Halimeh Shahzaei,Ms. c student of Climatology, Departement of Physical Geography, University of Sistan and Baluchistan, Zahedan, Iran. Mohsen Hamidianpour[1],Associate Professor, Departement of Physical Geography, University of Sistan and Baluchistan, Zahedan, Iran.  Mahsa Farzaneh,Ph. D Graduated. Climatology. Abstract Sensible HEAT flux and LATENT HEAT flux are among the variables that are closely related to temperature and humidity and show HEAT transfer on a surface. So, their changes can be considered related to changes in temperature and humidity. In this regard, the current research aims to analyze and reveal the climatic changes of Iran by examining the course of changes in sensible HEAT flux and LATENT HEAT and the ratio between the two. For this purpose, NCEP/NCAR reanalysis data including sensible and LATENT HEAT flux during the period 1948-2020 was used in Iran. Bowen coefficient was calculated from the ratio of these two HEAT fluxes. Interpolation methods were used for their spatio-temporal analysis. In addition, by using the non-parametric methods of Mann-Kendall and Shibsen, spatial and temporal changes were also investigated.   The first part of the results showed that, spatially, the Bowen coefficient is a function of latitude and roughness. And in terms of time, the lowest value corresponds to the month of January and the highest value corresponds to the month of July. The results of the second part show that the Bowen coefficient has a positive trend over time. Its upward trend indicates an increase in the dryness coefficient of the country. So that this situation can be seen in the positive trend and increase in temperature. Keywords: climate change, Bowen coefficient, global warming, spatio-temporal analysis.   [1]. Autehr corespound: Email: mhamidianpour@gep. usb. ac. ir

A review of past work in the subject areas of LATENT HEAT release in extratropical cyclones, within the concept of the potential vorticity framework or "PV thinking" is presented. It is also aimed to assess to what extent the conventional baroclinic instability theory can be applied to extratropical cyclones involving intense LATENT HEAT release. The main results of the previous studies concerning the effect of LATENT HEAT release on extratropical cyclones dynamics can be divided into two categories, depending on whether the impact of the diabatically generated PV anomaly on the baroclinic dynamics was very weak or strong. In the weak cases, cyclogenesis is primarily driven by baroclinic dynamics, with LATENT HEAT release playing a secondary role. LATENT HEATing influences the baroclinic dynamics as simply by superposing a positive PV anomaly near the cyclone center without significantly altering the PV structure elsewhere. On the other hand, a few studies reveal that LATENT HEAT release can enhance largely the cyclone intensity, particularly when the surface thermal gradients are weak and alter significantly the structure of upper-level PV and surface thermal anomalies. The low-level diabatically produced PV anomaly is able to substitute for the absent surface warm anomaly.

The growing need for energy, considering limited energy resources, pollution and global warming, have forced people to be more sensitive about the rate of energy consumption. Despite this fact, because of rising living standards, there is an increasing demand for cooling systems in buildings around the world. This increasing demand has led to a peak in electrical power consumption during hot summer days. Finding a solution for this peak is a new challenge for scientists. A leading option is to save available energy for use when it is needed. Saving the coldness of the night air for air conditioning during the hot summer days of tropical regions, instead of using common cooling devices, could be a proper opportunity to save energy. This idea is not only a good option for solving the electrical power imbalance between supply and demand, but also shifts the cooling energy use to O -peak periods and avoids peak demand charges. Phase Change Materials (PCM), because of their unique speci-fications, such as their capability of melting and freezing at a selected temperature, and their promising ability to reduce the dimensions of storage systems compared with usual storage systems (because they use the LATENT HEAT of the storage medium for thermal energy storage), can be used for this purpose. Initially, deriving a mathematical model for describing a HEAT exchanger packed with phase change Materials is essential. For this propose, a LATENT HEAT Thermal Energy Storage system (LHTES), containing at slabs of Phase Change Material (PEG 600), has been investigated numerically and experimentally. For the numerical investigation, a one-dimensional model considering axial conduction and using effective HEAT capacity has been proposed to describe the built LHTES. The results of the model and experiments were compared, and good agreements were achieved.

Energy crisis is a major challenge in the current world. LATENT HEAT thermal energy storage (LHTES) systems are known as equipment with promising performance by which thermal energy can be recovered. In the present study a comprehensive theoretical and experimental investigation is performed on a LHTES system containing PEG1000 as phase change material (PCM). Discussed topics can be categorized in three parts. At first, a one dimensional mathematical model is introduced for a HEAT exchanger containing flat slabs of PCM. To consider the LATENT HEAT of phase change, effective HEAT capacity is used in the model. Secondly, through eight experiments designed by using factorial method, effects of inlet air velocity and temperature on the outlet stream is investigated. The results proved that having a determined temperature difference between inlet air and the PCM in both hot and cold cycles can enhance the efficiency. Finally, the feasible applications of a LHTES system for controlling the temperature swing in a greenhouse is studied numerically and the results are compared with experimental values. As a result, by using this passive coolant system diurnal internal temperature can be reduced for 10°C.

In this paper, the effect of buoyancy force on the temperature change of the phase change materials which has been encapsulated in two pipes in a channel, is simulated numerically using Boussinesq approximation. An application of this topic is in air-conditioning, which uses ice in the pipes as PCM for coolant and the aim is calculating the PCM discharging time. The unsteady governing equations including continuity, momentum and energy in the fluid flow and phase change material for laminar flow regime, have been solved by the well-known SIMPLE method. The needed time to phase change material reach the inlet temperature of the fluid flow has been obtained and compared to the results of the lumped temperature assumption. The results show that the discharging time is 4,000 for Gr=5,000 and 70,000 for Gr=200,000. It is 25,000 for kr=0.5 and 34,000 for kr=1.5. Also, it is 11,000 for Cpr=103 and 28,000 for Cpr=104. Finally, it has been concluded that due to the fine mixing of PCM because of buoyancy force, the results are so closed to the results of the lumped temperature assumption for PCM.

Iran is connected to free ocean and other countries through Persian Gulf, Oman Sea and Caspian Sea. Thus, it is necessary to increase practical and scientific knowledge of seas rapidly.Knowing HEAT distribution in Persian Gulf helps one to forecast weather condition, predict the habitat of aquatic animals and plants, and provide other accurate information about sea.Generally the total in flow and outflow HEAT flux of the oceans should be zero; otherwise these oceans will freeze or will be very hot. The HEAT balance in Persian Gulf is examined in the article. Considering the point that the amount of rain and the inflow water to Persian Gulf is about 90cm/a and evaporation is 213cm/a, therefore, the amount of evaporation is 20-25 cm/a more than rain in Persian Gulf annually. Since the Persian Gulf volume of inflow and outflow is 0.186*106 and 0.169*106 m3 /s, the net transfer of HEAT to this Gulf is 25w/m2.The aim of this article is to explain this extra HEAT entering Persian Gulf by HEAT flux terms. The annual mean values of upward HEAT transfer due to solar radiation, sensible HEAT, LATENT HEAT and infrared radiation fluxes are 245, -4, 179 and 92 w/m3 respectively .The result is upward flux of about 22 w/m2 at the sea surface of this Gulf. This is in fair agreement with the extra HEAT transport in the Persian Gulf.

This paper numerically investigates the solidification performance improvement of phase change material in a triplex tube LATENT HEAT thermal energy storage unit by introducing an innovative longitudinal-parabolic fin. A numerical model based on the enthalpy-porosity approach is employed to simulate the discharging process. Simulation results reveal that the longitudinal-parabolic fins outperform the conventional straight fins in effectually increasing the phase change performance of the LATENT HEAT thermal energy storage unit. The complete discharging time of the triplex tube LATENT HEAT thermal energy storage unit with the proposed fin was reduced by up to 38.5% compared to that of the unit with straight fins. The study also investigates the influence of geometric parameters of the designed fin to achieve superior phase change material discharging efficiency. Effects of radial pitch and angular pitch of the longitudinal-parabolic fins on energy discharge time are studied by examining various cases under the constant total fins volume. Results infer that the radial pitch of parabolic fins has a moderate impact on solidification time improvement, while the angular pitch has a remarkable impact on reducing energy discharging time. Decreasing the angular pitch from 120° to 60° reduces the solidification time by 52.3%. The maximum of saving discharge time for the most efficient fin design is 61.8% in comparison with straight fins.