Numerical Model of a Rotating Prism Wall: Its Validation and Predicted Device Performance for a Variety of Situations

1989 ◽  
Vol 111 (3) ◽  
pp. 237-244 ◽  
Author(s):  
D. Faiman ◽  
D. Feuermann ◽  
M. Huleihil
Keyword(s):  
Temperature Distribution ◽  
Numerical Model ◽  
Full Scale ◽  
Device Performance ◽  
Standard Design ◽  
Trombe Wall ◽  
Storage Wall

A numerical model has been developed which describes the temperature distribution as a function of time within the storage elements of a Rotating Prism Solar Storage Wall. The model is tested against data obtained from a full-scale Rotating Prism Wall at Sede Boqer in Israel, and found to reproduce the measured temperatures extremely well. The thus validated model is used to predict the performance of such devices in various kinds of climate and to compare this performance with that to be expected from a nonvented Trombe Wall of standard design. In all cases the Rotating Prism Wall is found to provide considerably more useful energy than a nonvented Trombe Wall.

Multiphase Transient Slugging Flow in Subsea Oil and Gas Production

2016 ◽  
Author(s):  
Zhenhua Zhang ◽  
Longbin Tao
Keyword(s):  
Data Analysis ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Slug Flow ◽  
Field Data ◽  
Oil And Gas ◽  
Gas Production ◽  
Worst Case ◽  
Oil And Gas Production ◽  
Significant Difference

Slug flow in horizontal pipelines and riser systems in deep sea has been proved as one of the challenging flow assurance issues. Large and fluctuating gas/liquid rates can severely reduce production and, in the worst case, shut down, depressurization or damage topside equipment, such as separator, vessels and compressors. Previous studies are primarily based on experimental investigations of fluid properties with air/water as working media in considerably scaled down model pipes, and the results cannot be simply extrapolated to full scale due to the significant difference in Reynolds number and other fluid conditions. In this paper, the focus is on utilizing practical shape of pipe, working conditions and fluid data for simulation and data analysis. The study aims to investigate the transient multiphase slug flow in subsea oil and gas production based on the field data, using numerical model developed by simulator OLGA and data analysis. As the first step, cases with field data have been modelled using OLGA and validated by comparing with the results obtained using PIPESYS in steady state analysis. Then, a numerical model to predict slugging flow characteristics under transient state in pipeline and riser system was set up using multiphase flow simulator OLGA. One of the highlights of the present study is the new transient model developed by OLGA with an added capacity of newly developed thermal model programmed with MATLAB in order to represent the large variable temperature distribution of the riser in deep water condition. The slug characteristics in pipelines and temperature distribution of riser are analyzed under the different temperature gradients along the water depth. Finally, the depressurization during a shut-down and then restart procedure considering hydrate formation checking is simulated. Furthermore, slug length, pressure drop and liquid hold up in the riser are predicted under the realistic field development scenarios.

Block Treatment of Multi-Layer Wafers for the Development of a Numerical Model of a 300mm Batch Heat Treatment Furnace

2006 ◽  
Vol 15-17 ◽  
pp. 537-542
Author(s):  
Eun Yi Ko ◽  
Kyung Woo Yi
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Thermal Treatment ◽  
Radiation Heat Transfer ◽  
Great Influence ◽  
Vertical Direction ◽  
Treatment Furnace ◽  
Numerical Experimentation ◽  
Modeling Strategy

Of all the processing stages for wafers, interior temperature distribution in thermal treatment furnaces has a great influence on wafer properties. Therefore, internal temperature distribution is a key factor for operating a furnace. However, it is practically impossible to directly measure temperatures within the furnace, and consequently the need for a reliable numerical model to analyze temperature distribution is becoming increasingly urgent. Exact modeling of the processing is very difficult because the structure of the furnace used for thermal treatment is very complex, with large numbers of Si wafers stacked within. Therefore, simplified modeling is necessary. The modeling strategy of the present study is to reduce the radiation calculation domain and simplify the model by replacing the wafer stack region with a single block. It is necessary to determine the vertical and horizontal effective thermal conductivities of the block to reflect radiation heat transfer between wafers. In this study, calculations were performed through numerical experimentation, using r k as the heat transfer coefficient in the direction of the radius, and v k for the vertical direction. Using these calculated property values, the temperature distribution within a 300mm thermal treatment furnace can be obtained.

scholarly journals Experimental and Numerical Evaluation of Progressive Collapse Behavior in Scaled RC Beam-Column Subassemblage

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Rasool Ahmadi ◽  
Omid Rashidian ◽  
Reza Abbasnia ◽  
Foad Mohajeri Nav ◽  
Nima Usefi
Keyword(s):  
Numerical Model ◽  
Progressive Collapse ◽  
Experimental Tests ◽  
Resistance Mechanisms ◽  
Full Scale ◽  
Displacement Curve ◽  
Rc Beam ◽  
Rc Structures ◽  
Collapse Behavior ◽  
Column Removal Scenario

An experimental test was carried out on a 3/10 scale subassemblage in order to investigate the progressive collapse behavior of reinforced concrete (RC) structures. Investigation of alternative load paths and resistance mechanisms in scaled subassemblage and differences between the results of full-scale and scaled specimens are the main goals of this research. Main characteristics of specimen response including load-displacement curve, mechanism of formation and development of cracks, and failure mode of the scaled specimen had good agreement with the full-scale specimen. In order to provide a reliable numerical model for progressive collapse analysis of RC beam-column subassemblages, a macromodel was also developed. First, numerical model was validated with experimental tests in the literature. Then, experimental results in this study were compared with validated numerical results. It is shown that the proposed macromodel can provide a precise estimation of collapse behavior of RC subassemblages under the middle column removal scenario. In addition, for further evaluation, using the validated numerical model, parametric study of new subassemblages with different details, geometric and boundary conditions, was also done.

Modeling and Numerical Simulation of Laminated Thermoplastic Composites Manufactured by Laser-Assisted Automatic Tape Placement

2020 ◽  
Vol 35 (5) ◽  
pp. 471-480
Author(s):  
G. Ausias ◽  
G. Dolo ◽  
D. Cartié ◽  
F. Challois ◽  
P. Joyot ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Numerical Model ◽  
Pressure Field ◽  
Processing Parameters ◽  
Thermoplastic Composites ◽  
Final Thickness ◽  
Intimate Contact ◽  
Polymer Flow ◽  
Compaction Force ◽  
Heat Transfer Simulation

Abstract A comprehensive numerical model is developed for the simulation of the laser-assisted automated tape placement process of carbon fiber/thermoplastic composites. After being heated with a laser, the thermoplastic is welded with the help of a consolidation roller onto a substrate made up of layers of tapes bonded onto one another. Under the pressure applied by the roller, the thermoplastic flows and the tape reaches its final thickness. The numerical model is developed in three sequential steps that can be used to identify the required pressure and temperature distribution to achieve a good bond. Firstly, a heat transfer simulation is performed to determine the temperature distribution into the incoming tape under the consolidation roller. Secondly, a rheological model is developed to examine the polymer flow under the roller and to obtain the pressure field. Finally, the consolidation level between the substrate and the tape is investigated through the degree of intimate contact, which is related to the processing parameters such as the roller velocity, the laser power density and the compaction force.

Numerical Towing Model for LNG Carrier Approach in Exposed Environment Calibrated With Full-Scale Measurements and Operability Criterion

2021 ◽  
Author(s):  
Erwan Auburtin ◽  
Quentin Delivré ◽  
Jason McConochie ◽  
Jim Brown ◽  
Yuriy Drobyshevski
Keyword(s):  
Numerical Model ◽  
Degrees Of Freedom ◽  
Line Tension ◽  
Full Scale ◽  
Model Parameters ◽  
Wave Loads ◽  
Simplified Approach ◽  
Large Matrix ◽  
Multi Body ◽  
The Impact

Abstract The Prelude Floating Liquefied Natural Gas (FLNG) platform is designed to offload liquefied natural and petroleum gas products to carrier vessels moored in a Side-by-Side (SBS) configuration. Prior to the mooring operation, the carrier vessel is escorted and held alongside the FLNG with the assistance of tugs connected to her bow and stern to ensure sufficient control over the vessel in this critical phase. In order to better understand the impact of environmental conditions, to determine the optimum length, strength, material and configuration of the towline stretcher, and to estimate the maximum operable environments, coupled multi-body simulations have been performed in time domain. The numerical model, which considered both the LNG carrier and the forward tug, was calibrated using full-scale measurements of tug motions and tow line tension recorded during a real approach and berthing manoeuvre at Prelude FLNG. The measured environment effects were generated numerically and the model parameters were adjusted to reproduce the recorded behavior as accurately as possible. Since actions of the tug master are difficult to model numerically and only the statistical environment parameters are known, a simplified approach has been adopted for modelling the tug propulsion and steering using a combination of static forces, stiffness and linear and quadratic damping for relevant horizontal degrees of freedom. The calibrated numerical model was first subjected to several sensitivity assessments of the modelling level (single- or multi-body, inclusion of second-order wave loads, inclusion of forward speed). Then sensitivity studies were performed to help address operational requirements related to the wave height and direction, and the stretcher length and strength. The conclusions have been taken into consideration for the selection of the tow line configurations for future operations. Finally, the calibrated coupled LNG carrier and tug model was used to derive Prelude-specific tug operability criteria that may be used for decision-making based on weather forecasts, prior to the SBS offloading operations. A large matrix of swell and wind driven waves was simulated over a range of wave heights, periods, directions and static towing forces to allow a criterion to be developed based on a stochastic extreme tow line tension. Such criterion considers relevant wave parameters while remaining simplified enough for easy use in operations. This paper describes the assumptions and process to numerically model the towing configuration and calibrate the different coefficients, discusses the results obtained for the various sensitivities, and explains the operability criteria. Important conclusions and lessons learnt are also shared.

Initial Results of Monitoring the Temperature on the Facade of Office Building

2019 ◽  
Vol 887 ◽  
pp. 411-418
Author(s):  
Peter Juras ◽  
Radoslav Ponechal ◽  
Daniela Štaffenová
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Full Scale ◽  
Office Building ◽  
Wind Flow ◽  
Climate Conditions ◽  
Outdoor Climate ◽  
Measurement Units ◽  
Weather Stations ◽  
Initial Results

This paper deals with creating of the unique measurement units on the building façade, which enable the possibility to conduct a full-scale measurement of the outdoor climate parameters around the building. The façade of the Research center building, which is a part of University of Zilina campus, is equipped with 36 weather stations to measure the outdoor climate conditions and impact of the building on the approaching wind flow, air temperature distribution, solar radiance impact on the façade etc.In this article, the change of temperatures within the time and place on the facade (sides, position, time), is monitored. This takes into account the surroundings of the building and the temperature on the façade and comparison to the measured “basic” air temperature.

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