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EFFECTS OF VISCOUS DISSIPATION ON THERMALLY DEVELOPING FORCED CONVECTION IN A POROUS SATURATED CIRCULAR TUBE WITH AN ISOFLUX WALL

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Applied Mathematics and Mechanics(English Edition) 2006年第5期27卷 617-626页

作者： kamel hooman Alireza Pourshaghaghy Arash Ejlali Mechanical Engineering Department Bushehr Engineering FacultyPersian Gulf UniversityBushehrIran Mechanical Engineering Department Faculty of EngineeringUniversity of TehranTehranIran Legal and Contracts Petropars Co.TehranIran

The viscous dissipation effect on forced convection in a porous saturated circular tube with an isoflux wall is investigated on the basis of the Brinkman flow model. For the thermally developing region, a numerical study is reported while a perturbation analysis is presented to find expressions for the temperature profile and the Nusselt number for the fully developed region. The fully developed Nusselt number found by numerical solution for the developing region is compared with that of asymptotic analysis and a good degree of agreement is observed.

关键词： forced convection viscous dissipation Brinkman model Darcy number Nusselt number

Computational fluid dynamics applied to high temperature hydrogen separation membranes

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Frontiers of Chemical Science and Engineering 2012年第1期6卷 3-12页

作者： Guozhao JI Guoxiong WANG kamel hooman Suresh BHATIA Joao C. DINIZ da COSTA School of Chemical Engineering the University of Queensland Brisbane 4072 Australia School of Mechanical and Mining Engineering the University of Queensland Brisbane 4072 Australia

This work reviews the development of computational fluid dynamics （CFD） modeling for hydrogen separation, with a focus on high temperature membranes to address industrial requirements in terms of membrane systems as contactors, or in membrane reactor arrange- ments. CFD modeling of membrane,.s attracts interesting challenges as the membrane provides a discontinuity of flow, and therefore cannot be solved by the Navier-Stokes equations. To address this problem, tile concept of source has been introduced to understand gas flows on both sides or domains （feed and permeate） of the membrane. This is an important solution, as the gas flow and concentrations in the permeate domain are intrinsically affected by the gas flow and concentrations in the feed domain and vice-versa. In turn, the source term will depend on the membrane used, as different membrane materials comply with different transport mechanisms, in addition to varying gas selectiv- ity and fluxes. This work also addresses concentration polarization, a common effect in membrane systems, though its significance is dependent upon the performance of the membrane coupled with the operating conditions. Finally, CFD modeling is shifting from simplified single gas simulation to industrial gas mixtures, when the mathematical treatment becomes more complex.

关键词： membrane gas separat:ion computationalfluid dynamics concentration polarization hydrogen

Thermal characteristics of melting of a phase change material enhanced by a stainless-steel 304 periodic structure

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Energy Storage and Saving 2023年第2期2卷 442-448页

作者： Chunrong Zhao Michael Opolot Patrick Keane Ji Wang Ming Liu Frank Bruno Simone Mancin kamel hooman School of Mechanical and Mining Engineering The University of QueenslandBrisbane4072Australia School of Aerospace Mechanical and Mechatronic EngineeringThe University of SydneyNSW2006Australia Future Industries Institute University of South AustraliaMawson Lakes5095Australia Department of Management and Engineering University of PadovaVicenza36100Italy Department of Process and Energy Delft University of TechnologyLeeghwaterstraat 392628 CB DelftThe Netherlands

In this work,melting of a high-temperature inorganic phase change material(PCM)eutectic(with a melting point of 569℃)within a vertical cylindrical tank has been experimentally *** promote the heat transfer rate,a periodic structure that is constructed by a commercial SS-304 mesh screen has been considered and immersed into the PCM *** characteristics of the PCM-periodic structure tank under different initial temperatures(450,490 and 546℃)and wall temperatures(620,640,660,680 and 700℃),are then investigated and *** presented experimental data can facilitate practical engineers to find the best operating condition of similar PCM tanks;meanwhile,it can also be employed for the investigation of thermal response of transient heat conduction before melting starts.

关键词： Melting enhancement Thermal characteristics Experiment

Entropy generation analysis of thermally developing forced convection in fluid-saturated porous medium

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Applied Mathematics and Mechanics(English Edition) 2008年第2期29卷 229-237页

作者： K.hooman A.Ejlali F.hooman School of Engineering The University of QueenslandBrisbaneAustralia Fix Equipment Lead Engineer Namavaran Delvar Engineering and Construction CompanyTehranIran Chemical Engineering Department Sharif University of TechnologyTehranIran

Entropy generation for thermally developing forced convection in a porous medium bounded by two isothermal parallel plates is investigated analytically on the basis of the Darcy flow model where the viscous dissipation effects had also been taken into account. A parametric study showed that decreasing the group parameter and the Peclet number increases the entropy generation while for the Brinkman number the converse is true. Heatline visualization technique is applied with an emphasis on the Br 〈 0 case where there is somewhere that heat transfer changes direction at some streamwise location to the wall instead of its original direction, i.e., from the wall.

关键词： entropy generation porous media heatline energy flux vectors forced convection

Scour around submarine pipes due to high-amplitude transient waves

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Water Science and Engineering 2020年第2期13卷 154-161页

作者： Hassan Vosoughi hooman Hajikandi Department of Civil Engineering Central Tehran BranchIslamic Azad UniversityTehran ***Iran

Estimation of scour dimensions below submarine pipelines is a vital step in designing offshore *** events like tsunami waves produce strong erosive forces below the underwater pipes,apt to create scour holes,jeopardizing the safety of the *** the importance of this issue,previous studies have mainly focused on steady flow cases,and the scour pattern below submarine pipes induced by high-amplitude transient waves has rarely been *** paper reports the results of 40 experimental runs on transient wave-induced scour below a model pipe in a laboratory flume under a variety of initial *** variables included the bed particle size and gradation,initial water depth,wave height,and slope of the bed *** were generated by a sudden release of water from a sluice gate,installed in the middle of the flume.A pressure transducer data acquisition system was used to record the wave heights at different time *** results indicate that,with a shallower initial depth of flow,the scour depth is relatively *** was also found that there exists a direct correlation between the induced wave height and the size of the scour *** was observed that,in clear water conditions,the size of the scour hole in coarse sediments is smaller,while in live-bed conditions,larger scour holes are created in coarser *** was also observed that at high wave amplitudes,the live-bed conditions are dominant,and consequently the bed elevation is altered.

关键词： Submarine pipe Scour hole Transient wave Flume experiment Live-bed condition Sediment

The influence of environmental variables on distribution patterns of Irano-Turanian forests in Alborz Mountains, Iran

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Journal of Mountain Science 2016年第8期13卷 1375-1386页

作者： hooman RAVANBAKHSH Alireza MOSHKI Faculty of Desert Studies Semnan University

Topographic and edaphic variables are the main ecological factor determining species spatial variability on mountainous forests. A field study was performed in central Alborz to investigate how the edaphic and topographic parameters can affect the tree and shrub communities. Initially, 27 forest stands were identified and the homogeneous units were separated regarding physiognomy. In each single homogeneous unit, one random sample plot （1000 m^2） and totally 43 plots were established. In each plot, the presence and abundance of all trees and shrubs were recorded and four soil samples were taken from depths of 0-5 and 5-20 cm. Concerning classification results, eight different forest communities were identified. The lowest and highest soil pH values were observed in Malus orientalis and pistacia-Amygdalus communities, respectively. The water saturation percent of pure- and mixed Juniperus excelsa and Rhus coriaria was the highest amongst communities. The clay content was the highest in pure ***. The 0-5 organic matter and Nitrogen content in mixed J. excelsa were significantly higher than pure J. excelsa and other communities. The CCA （Canonical Correspondence Analysis） altitude, precipitation, pH, results indicated that the EC, SP, clay and CaCO3 are the most important factors determine the distribution of trees and shrub in central Alborz.

关键词： Irano-Turanian Mountainouswoodlands Multivariate analysis Species-environment relationship

Simulation and optimization approach for uncertainty-based short-term planning in open pit mines

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International Journal of Mining Science and Technology 2018年第2期28卷 153-166页

作者： Shiv Prakash Upadhyay hooman Askari-Nasab Department of Civil and Environment Engineering School of Mining and Petroleum Engineering University of Alberta

Accuracy in predictions leads to better planning with a minimum of opportunity lost. In open pit mining,the complexity of operations, coupled with a highly uncertain and dynamic production environment,limit the accuracy of predictions and force a reactive planning approach to mitigate deviations from original plans. A simulation optimization framework/tool is presented in this paper to account for uncertainties in mining operations for robust short-term production planning and proactive decision making. This framework/tool uses a discrete event simulation model of mine operations, which interacts with a goalprogramming based mine operational optimization tool to develop an uncertainty based short-term schedule. Using scenario analysis, this framework allows the planner to make proactive decisions to achieve the mine's operational and long-term objectives. This paper details the development of simulation and optimization models and presents the implementation of the framework on an iron ore mine case study for verification through scenario analysis.

关键词： Scheduling Simulation optimization Short-term planning Mine operational planning Truck-shovel allocation

On the Relation Between Symmetry of Radio Galaxies and Their Physical Parameters

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Research in Astronomy and Astrophysics 2024年第9期24卷 37-59页

作者： Mohsen Javaherian Halime Miraghaei hooman Moradpour Research Institute for Astronomy and Astrophysics of Maragha(RIAAM) University of MaraghehP.O.Box 55136-553MaraghehIran

Gravity as a fundamental force plays a dominant role in the formation and evolution of cosmic objects and leaves its effect in the emergence of symmetric and asymmetric ***,analyzing the symmetry criteria allows us to uncover mechanisms behind the gravity interaction and understand the underlying physical processes that contribute to the formation of large-scale structures such as *** use a segmentation process using intensity thresholding and the k-means clustering algorithm to analyze radio galaxy *** employ a symmetry criterion and explore the relation between morphological symmetry in radio maps and host galaxy *** properties(stellar mass,black hole mass,optical size(R_(50)),concentration,stellar mass surface density(μ_(50)),and stellar age)and radio properties(radio flux density,radio luminosity,and radio size)are *** found that there is a correlation between symmetry and radio size,indicating larger radio sources have smaller symmetry ***,size of radio sources should be considered in any investigation of *** correlations are also observed with other properties,such as R_(50)for FRI galaxies and stellar *** compare the symmetry differences between FRI and FRII radio *** galaxies show higher symmetry in 1.4 GHz and 150 MHz *** the influence of radio source sizes,we discovered that this result is independent of the sizes of radio *** findings contribute to our understanding of the morphological properties and analyses of radio galaxies.

关键词： methods:data analysis techniques:image processing catalogs galaxies:nuclei galaxies:distances and redshifts

Integrated Intelligent Electromagnetic Radiator Design for Future THz Communication:A Review

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Chinese Journal of Electronics 2022年第3期31卷 499-515页

作者： LU Xuyang Venkatesh Suresh Saeidi hooman Sengupta Kaushik UM-SJTU Joint Institute Shanghai Jiao Tong University Electrical and Computer Engineering Princeton University

Advances in 6 G communication changes how machines and humans interact. The blossom of new applications demands significantly higher data bandwidth while preserving the mobility and sustainability of electronic wireless communication systems. It also demands an integrable system that allows convenient interactions between communication units and signal processing units.A review of CMOS-based THz communication system solutions is presented, with a focus on novel systematic EM-circuit co-design philosophy. This review starts with a review of THz power generation, followed by the discussion of THz localization and THz beamforming for efficient high-throughput communication.

关键词： submillimetre wave generation efficient high-throughput communication THz power generation THz localization integrable system integrated intelligent electromagnetic radiator design electronic wireless communication systems sustainability 6G communication communication system solutions future THz communication signal processing units mobility 6G mobile communication CMOS integrated circuits THz beamforming integrated circuit design array signal processing communication units CMOS systematic EM-circuit co-design philosophy