scholarly journals Simulation study of solar chimney assisted solarium.

2021 ◽  
Author(s):  
Afrooz Ravanfar
Keyword(s):  
Cross Section ◽  
Thermal Response ◽  
Ventilation Rate ◽  
Critical Parameters ◽  
Thermal Engineering ◽  
First Principle ◽  
Solar Chimney ◽  
Modelling Method ◽  
Simulation Results ◽  
Thermal Simulations

The objective of this study is to develop a modelling method for optimizing the design of a solar chimney integrated solarium to maximize the ventilation rate in the solarium. A thermal model is developed and implemented in SIMULINK to simulate the thermal response of the solarium combined with a solar chimney based on the first principle of thermal engineering. Thermal simulations are performed for critical summer days. The greenhouse air temperature and its ventilation rate with various geometrical configurations are calculated on the basis of solar irradiance intensity and ambient temperature. The preliminary numerical simulation results show that a solar chimney, combined with an appropriately inclined roof of a solarium, would be a better option for ventilation improvement in the solarium. The solarium height and solarium/solar chimney cross section areas are the critical parameters. The combination of a shorter solar chimney with a high solarium would be suitable for Toronto.

scholarly journals Simulation study of solar chimney assisted solarium.

2021 ◽  
Author(s):  
Afrooz Ravanfar
Keyword(s):  
Cross Section ◽  
Thermal Response ◽  
Ventilation Rate ◽  
Critical Parameters ◽  
Thermal Engineering ◽  
First Principle ◽  
Solar Chimney ◽  
Modelling Method ◽  
Simulation Results ◽  
Thermal Simulations

The objective of this study is to develop a modelling method for optimizing the design of a solar chimney integrated solarium to maximize the ventilation rate in the solarium. A thermal model is developed and implemented in SIMULINK to simulate the thermal response of the solarium combined with a solar chimney based on the first principle of thermal engineering. Thermal simulations are performed for critical summer days. The greenhouse air temperature and its ventilation rate with various geometrical configurations are calculated on the basis of solar irradiance intensity and ambient temperature. The preliminary numerical simulation results show that a solar chimney, combined with an appropriately inclined roof of a solarium, would be a better option for ventilation improvement in the solarium. The solarium height and solarium/solar chimney cross section areas are the critical parameters. The combination of a shorter solar chimney with a high solarium would be suitable for Toronto.

scholarly journals Nanodevices Tend to Be Round

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 330
Author(s):  
Georges Pananakakis ◽  
Gérard Ghibaudo ◽  
Sorin Cristoloveanu
Keyword(s):  
Diffusion Process ◽  
Thermal Diffusion ◽  
Cross Section ◽  
Gate Voltage ◽  
Supportive Evidence ◽  
Inversion Mode ◽  
Nanowire Transistor ◽  
Junctionless Transistor ◽  
Simulation Results ◽  
Thermal Diffusion Process

Under several circumstances, a nanowire transistor with a square cross-section behaves as a circular. Taking the Gate-All-Around junctionless transistor as a primary example, we investigate the transition of the conductive region from square to circle-like. In this case, the metamorphosis is accentuated by smaller size, lower doping, and higher gate voltage. After defining the geometrical criterion for square-to-circle shift, simulation results are used to document the main consequences. This transition occurs naturally in nanowires thinner than 50 nm. The results are rather universal, and supportive evidence is gathered from inversion-mode Gate-All-Around (GAA) MOSFETs as well as from thermal diffusion process.

Thermal Response and Ablation Research of EPDM Thermal Protection Material in Ramjet

2015 ◽  
Vol 1092-1093 ◽  
pp. 534-538
Author(s):  
Xiong Chen ◽  
Hai Feng Xue ◽  
Hua Liang
Keyword(s):  
Heat Transfer ◽  
Heat Load ◽  
Thermal Protection ◽  
Thermal Response ◽  
Transfer Model ◽  
Back Face ◽  
Ground Test ◽  
Simulation Results ◽  
Face Temperature ◽  
Scanning Electron

Thermal protection materials are required to preserve the metal components of motor that suffer severe heat load. The research on thermal response of insulation of ramjet combustion chamber was carried out by the ground test and numerical simulation. During the working time of the ramjet, the back-face temperature of the thermal protection material was measured. The scanning electron microscope of samples was investigated. The calculation of thermo-chemical flow was solved by the CFD software FLUENT to provide the heat load boundary for simulation of heat transfer of EPDM insulation. The heat transfer model was solved by the FEA software ANSYS. Comparison of the temperature profile at the ablating surface between calculation and measurement shows the two results agree with each other. The simulation results can provide the temperature rising trend of insulation in a certain extent.

Natural-Ventilation Flow in a 3-D Room Fitted With Solar Chimney

2012 ◽  
Author(s):  
B. P. Huynh
Keyword(s):  
Heat Flux ◽  
Flow Pattern ◽  
Natural Ventilation ◽  
Air Flow ◽  
Ventilation Rate ◽  
High Heat Flux ◽  
Solar Chimney ◽  
Solar Heat ◽  
Solar Heat Flux ◽  
Inlet Opening

Natural-ventilation flow induced in a real-sized rectangular-box room fitted with a solar chimney on its roof is investigated numerically, using a commercial CFD (Computational Fluid Dynamics) software package. The chimney in turn is in the form of a parallel channel with one plate being subjected to uniform solar heat flux. Ventilation rate and air-flow pattern through the room are considered in terms of the heat flux for two different locations of the room’s inlet opening. Chien’s turbulence model of low-Reynolds-number K-ε is used in a Reynolds-Averaged Navier-Stokes (RANS) formulation. It is found that ventilation flow rate increases quickly with solar heat flux when this flux is low, but more gradually at higher flux. At low heat flux, ventilation rate is not significantly affected by location of the inlet opening to the room. On the other hand, at high heat flux, ventilation rate varies substantially with the opening’s location. Location of the inlet opening to the room also affects strongly the air-flow pattern. In any case, ample ventilation rate is readily induced by the chimney.

scholarly journals Phononic Band Gap and Free Vibration Analysis of Fluid-Conveying Pipes with Periodically Varying Cross-Section

2021 ◽  
Vol 11 (21) ◽  
pp. 10485
Author(s):  
Hao Yu ◽  
Feng Liang ◽  
Yu Qian ◽  
Jun-Jie Gong ◽  
Yao Chen ◽  
...  
Keyword(s):  
Free Vibration ◽  
Band Gap ◽  
Cross Section ◽  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Critical Parameters ◽  
Mode Shapes ◽  
Beam Model ◽  
The Impact ◽  
Fluid Conveying Pipes

Phononic crystals (PCs) are a novel class of artificial periodic structure, and their band gap (BG) attributes provide a new technical approach for vibration reduction in piping systems. In this paper, the vibration suppression performance and natural properties of fluid-conveying pipes with periodically varying cross-section are investigated. The flexural wave equation of substructure pipes is established based on the classical beam model and traveling wave property. The spectral element method (SEM) is developed for semi-analytical solutions, the accuracy of which is confirmed by comparison with the available literature and the widely used transfer matrix method (TMM). The BG distribution and frequency response of the periodic pipe are attained, and the natural frequencies and mode shapes are also obtained. The effects of some critical parameters are discussed. It is revealed that the BG of the present pipe system is fundamentally induced by the geometrical difference of the substructure cross-section, and it is also related to the substructure length and fluid–structure interaction (FSI). The number of cells does not contribute to the BG region, while it has significant effects on the amplitude attenuation, higher order natural frequencies and mode shapes. The impact of FSI is more evident for the pipes with smaller numbers of cells. Moreover, compared with the conventional TMM, the present SEM is demonstrated more effective for comprehensive analysis of BG characteristics and free vibration of PC dynamical structures.

Cross-Section Shape Optimization of Expandable Cased-Hole Liners

2010 ◽  
Vol 156-157 ◽  
pp. 1141-1145
Author(s):  
Ben Ma ◽  
Hai Qing Li ◽  
Xu Deng ◽  
Min Li
Keyword(s):  
Cross Section ◽  
Branch Pipe ◽  
Field Tests ◽  
Forming Process ◽  
Molding Process ◽  
Compression Process ◽  
Proper Position ◽  
Cross Section Shape ◽  
Section Shape ◽  
Simulation Results

Expandable cased-hole liners is to solve the sealing problem of level six multilateral wells. It is a trigeminal expandable tube which is usually prefabricated on the ground and re-expanded when placed in the proper position. In this paper, the trigeminal expandable tubular compression molding process of the pre-forming stage is mainly studied. In this compression process, both sides of the branch pipe should be compressed to a certain shape in order to successfully enter the main borehole; meanwhile, we want to make sure that failures such as rupture do not occur in the subsequent expansion process. According to the theory about sheet metal bending forming process, three different shapes of the mold are designed to control the cross-section shape of the compressed trigeminal expandable tube so that it meets the application requirements. Rack-shaped cross-section is finally selected as a reference of the best through simulation of compression process and comparative analysis of simulation results. At last, field tests show that this cross-section shape is compatible with the theoretical and simulation results.

Design of Printed Circuit Heat Exchanger (PCHE) for LNG Re-Gasification System

2017 ◽  
Author(s):  
Seok Ho Yoon ◽  
Jeong Heon Shin ◽  
Dong Ho Kim ◽  
Jun Seok Choi
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Optimal Design ◽  
Cross Section ◽  
Diffusion Bonding ◽  
Analytical Calculation ◽  
Analytical Tool ◽  
Printed Circuit ◽  
Simulation Results ◽  
Semicircular Cross Section

In this paper, we present the ongoing process of the research and development of the Printed Circuit Heat Exchanger (PCHE) on Floating Storage Regasification Unit (FSRU). We performed a structural simulation work to find the optimal design of fluid channels on heat transfer plates, fabricated the heat transfer plates, and calculated the capacity of the PCHE using our analytical tool. In the simulation work, the plates having channels of 1 mm semicircular cross section were designed by varying the wall thickness between channels. At a temperature, 1373 K, compressing pressures were varied as 30, 85.7, and 500 bars. Based on the simulation results, we fabricated and bonded heat transfer plates using the diffusion bonding equipment which our department developed. Then, the sizing of PCHE was done with analytical calculation for the developing PCHE on FSRU.

scholarly journals Numerical Simulation of A Cubic Spout-Fluid Bed: Influences of Inlet Gas Temperature and Jet to Bed Cross-Section Ratio

2020 ◽  
Vol 18 (3) ◽  
Author(s):  
Ali Rahmani ◽  
Mohsen Tamtaji ◽  
Asghar Molaei Dehkordi
Keyword(s):  
Cross Section ◽  
Circulation Pattern ◽  
Particle Simulation ◽  
Cross Section Ratio ◽  
Gas Temperature ◽  
Section Ratio ◽  
Fluid Bed ◽  
Discrete Particle Simulation ◽  
Simulation Results

AbstractIn this paper, we study the role of inlet gas temperature and jet to bed cross-section ratio on hydrodynamics and circulation patterns of particles in a spout-fluid bed. The system is modeled using CFD-TFM approach based on Eulerian-Eulerian method. Simulation results are validated by experimental data measured by (Link 2008. “PEPT and Discrete Particle Simulation Study of Spout-fluid Bed Regimes.” Aiche Journal 54 (5): 1189–202). First, the sensitivity analysis of simulation results versus the most significant parameters are conducted to find the optimum values for each parameter. Subsequently, the role of inlet gas temperature and cross-section ratios are studied in detail. The simulation results clearly demonstrate that increasing the inlet gas temperature raises particles’ velocity in the bed and affects the circulation pattern in annulus region. Additionally, it is shown that higher gas temperature leads to existence of hot spots in the annulus region. In case of jet to bed cross-section ratio, using larger ratios results in higher velocities and lower pressure drop along the bed.

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