23 research outputs found
Different Proposed Models to Mapping MDA to RUP
Reducing of the production expenses and preventing software intricacies is one of the software engineering aims. So, many method and methodology such as object-oriented, component-oriented, aspect-oriented, and service-oriented are preferred for developing software engineering. Model driven development is one of the methodologies that had considered recently and is growing rapidly .modeling the program logic and then changing model to a practicable code by some tool automatically will be the aim of the model driven development. In this paper we investigate some model driven methodology and also we’ll preferred MDA mapping to RUP.DOI:http://dx.doi.org/10.11591/ijece.v3i3.224
Eulerian ISPH Method for Simulating Internal Flows
In this article the possibility to use Eulerian approach in the conventional ISPH method in simulation of internal fluid flows is studied. The use of Eulerian approach makes it possible to use non-uniform particle distributions to increase the resolution in the sensitive parts of the domain, different boundary conditions can be employed more freely and particle penetration in the solid walls and tensile instability no longer require elaborate procedures. The governing equations are solved in an Eulerian framework containing both the temporal and local derivatives which make the momentum equations non-linear. Some special treatment and smaller time steps are required to remedy this non-linearity of the problem. In this study, projection method is used to enforce incompressibility with the evaluation of an intermediate velocity and then this velocity is projected on the divergence-free space. This method is applied to the internal fluid flows in a shear-driven cavity, Couette flow, a flow inside a duct with variable area and flow around a circular cylinder within a constant area duct. The results are compared with the results of Lagrangian ISPH and WCSPH methods as well as finite volume and Lattice Boltzmann grid based schemes. The results of the studied scheme have the same accuracy for velocity field and have better accuracy in pressure distribution than ISPH and WCSPH methods. Non-uniform particle distributions are also studied to check the applicability of this method and Good agreement is also observed between uniform and non-uniform particle distributions
THEORETICAL AND EXPERIMENTAL STUDY OF THERMAL AND HYDRODYNAMIC CONDITIONSIN A SHALLOW WATER LAYER HEATED FROM BELOW BY SUBMERGED HORIZONTAL CYLINDERS.
Abstract not availabl
Numerical and experimental study of an under-ground water reservoir, cistern
This article presents experimental and numerical study of an under-ground water reservoir (cistern) during six months operation in a semi-arid region. The cistern with one dome, four windcatchers and a water reservoir is located in Lar, a hot arid city at south of Iran. Outdoor and indoor air temperature and humidity, water temperature in three depths and dome surface temperature were measured using a data logging system. The results show that the average air humidity inside the cistern was almost constant during the experiments but its slight variation during a day follows inside air temperature changes. The inside air temperature was always lower than the ambient temperature and inside and outside average air temperature difference was about 6 °C. The difference was slightly higher in the hot seasons. The water reservoir was also modeled in 2D, axisymmetric and quasi steady numerical simulation for six months of operation. Highly stratified water temperature distribution was observed in the numerical results as well as the experimental measurements
Influence of Iwans on the Thermal Comfort of Talar Rooms in the Traditional Houses: A Study in Shiraz, Iran
In traditional buildings many climatic strategies have been used to provide indoor thermal comfort in south and central parts of Iran. A common element is called an iwan. This study investigates the indoor thermal comfort of a room adjoined to a talar in a traditional house which has an iwan, in Shiraz, Iran. The data related to the temperature and relative humidity of the room are used to calculate the thermal comfort index of PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) by considering the following two cases: a talar room with an iwan and one without an iwan, by means of DesignBuilder software. For the purpose of validation, the air temperature and relative humidity of the talar room with an iwan were measured over 10 days and compared to the results of the simulation. Having a valid simulation, computation was conducted for the selected house in various cases for an annual passive operation of calculating PMV and PPD. The numerical results revealed that the talar room adjoined to an iwan located in the south front of the courtyard had relatively good conditions during the hot months, including June and July. In addition, it could provide fully satisfactory comfort conditions during August and September. According to the results, it is found that the iwan makes a talar room 62% more desirable for the hot months in comparison with a talar room without an iwan
New Nusselt number correlations for developing and fully developed laminar flows in concentric circular annular ducts
Concentric circular annular ducts are common and important elements in fluid flow and heat transfer equipment, including chemical mixing devices and heat exchangers. There are many problems involving heat transfer in concentric annuli which require accurate heat transfer coefficients for laminar and turbulent flows. This study proposes new correlations for the local and average Nusselt numbers in hydrodynamically fully developed and thermally developing or fully developed regions of laminar flows. The correlations are developed based on the results of available series solutions for four fundamental boundary conditions. The correlations use exponential and power law functions of dimensionless axial and radial lengths; they are more accurate, easier to use, more similar to fundamental analytical solutions, and require fewer terms. The maximum and average differences between the local Nusselt numbers predicted by the proposed correlations and the analytical data are respectively 2.04% and 0.38% for fully developed flows and 9.97% and 1.35% for developing flows. Moreover, the maximum and average differences for average Nusselt numbers are 4.59% and 2.01%, respectively. The results show that the proposed correlations are more practical and they can predict the developing, fully developed, and average Nusselt numbers with excellent accuracy across a wider range of flow conditions
THREE-DIMENSIONAL NUMERICAL LAMINAR CONVECTION HEAT TRANSFER AROUND LATERAL PERFORATED FINS
The Impact of Archetype Patterns in Office Buildings on the Annual Cooling, Heating and Lighting Loads in Hot-Humid, Hot-Dry and Cold Climates of Iran
Extensive cost in the building industry comes from cooling and heating to create thermal comfort. Hence, it is necessary to utilize passive solutions, in addition to suitable design, in order to reduce energy consumption. This research attempts to investigate the impact of archetype patterns in office buildings on annual energy consumption for cooling, heating and daylight loads. For this purpose, the DesignBuilder software was used to compare the forms. In this study, four conventional construction forms were considered, including the single and dense form, central courtyard buildings, U form and linear form, and each was considered with two, four and six-stories. Forms were simulated in the three cities of Bushehr, Shiraz and Tabriz, with hot-humid, hot-dry and cold climates, respectively. The results revealed that the office building with a linear form in Bushehr had the lowest energy consumption in the two and four-story forms, and also in the six-story form, the central courtyard form had the lowest energy consumption. Additionally, the central courtyard forms in Tabriz and Shiraz had the lowest energy consumption in all cases. Finally, the linear form possessed the most natural daylight through all of the studied cases for the three cities in terms of natural light gain
The Optimum Window-to-Wall Ratio in Office Buildings for Hot‒Humid, Hot‒Dry, and Cold Climates in Iran
About half of the energy loss in buildings is wasted through windows. Determining the optimum window-to-wall ratio (WWR) for different building facades would reduce such energy losses. The optimum WWR is the window area that minimizes the total annual energy of cooling, heating, and lighting. The purpose of this study is to investigate the optimum WWR of different facades of an office building. For this purpose, a sample building is simulated by means of DesignBuilder software in order to investigate the annual solar heat gain, cooling load, heating load, and lighting consumption for the three cities of Bushehr, Shiraz, and Tabriz, and optimum window areas of office buildings for the three cities are determined. Based on the results, the optimum window area for the north building facade for all climates is 20–30%. This amount for the southern facade of the building in Bushehr, Shiraz, and Tabriz is, respectively, 20–30%, 10–30%, and 20–50%. The optimum window area for the eastern and western building facades in Bushehr is 30–50%; in Tabriz it is 40–70%, and in Shiraz it is 20–60% and 40–70%, respectively. The difference between the maximum and minimum energy consumption with different window areas in Bushehr and Shiraz is 20–100% and in Tabriz it is 16–25%