Numerical Simulation of the Charging of Liquid Storage Tanks: Comparison With Experiment

1989 ◽  
Vol 111 (3) ◽  
pp. 225-231 ◽  
Author(s):  
M. F. Lightstone ◽  
G. D. Raithby ◽  
K. G. T. Hollands
Keyword(s):  
Plug Flow ◽  
Energy System ◽  
Hot Water ◽  
Storage Tanks ◽  
Fluid Turbulence ◽  
Liquid Storage ◽  
Model Predictions ◽  
Future Work ◽  
Insight Into ◽  
Good Agreement

The degree of thermal stratification maintained in hot water storage tanks has a significant impact on the performance of a solar energy system. This paper presents an axisymmetric finite volume model analysis of the charging of a tank with hot water, and compares the predictions with experimental results from the literature. The results show the capabilities and deficiencies of such a modeling technique for this type of problem. The importance of inlet fluid turbulence to tank destratification is demonstrated and inclusion of a simple turbulence model is found sufficient to yield good agreement with measurement. The model predictions also provide insight into when a simple one-dimensional plug flow model will be adequate. In addition, the model is used to evaluate the effect during charging of heat conduction in the tank wall on the temperature field in the fluid. Recommendations are made regarding future work on the development of detailed numerical codes for simulating the charging of liquid storage tanks.

Performance of cylindrical liquid storage tanks in Silakhor, Iran earthquake of March 31, 2006

2007 ◽  
Vol 40 (4) ◽  
pp. 173-182 ◽  
Author(s):  
Sassan Eshghi ◽  
Mehran S. Razzaghi
Keyword(s):  
Linear Time ◽  
Time History ◽  
Storage Tanks ◽  
Liquid Storage ◽  
History Analysis ◽  
History Of ◽  
Flexible Foundation ◽  
Theoretical Results ◽  
Strong Ground ◽  
Good Agreement

Several on-ground cylindrical liquid storage tanks experienced strong ground motion during the “Silakhor” earthquake of March 31, 2006 in western Iran, and some of the tanks suffered minor to moderate damage. In this study two of the affected tanks that were located close to the station of recording the time history of the earthquake were investigated. Responses of these tanks to the earthquake were estimated using published methods and also non-linear time history analysis, for both rigid foundation and flexible foundation assumptions. Theoretical results were compared and were generally in good agreement with the observed performance of tanks during the earthquake. For the broad tank uplift displacements observed from the earthquake matched quite closely the predictions of numerical analysis and some of the published methods, although there was a significant variation in the predictions of various methods. It was also shown that axial stresses in tank shells uplifting under earthquake are very dependent on the rigidity of the foundation.

scholarly journals A Flow Rate Dependent 1D Model for Thermally Stratified Hot-Water Energy Storage

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2611
Author(s):  
Joseph Rendall ◽  
Fernando Karg Bulnes ◽  
Kyle Gluesenkamp ◽  
Ahmad Abu-Heiba ◽  
William Worek ◽  
...  
Keyword(s):  
Root Mean Square Error ◽  
Mean Square Error ◽  
Flow Rate ◽  
Plug Flow ◽  
Water Storage ◽  
Eddy Diffusivity ◽  
Hot Water ◽  
Mean Square ◽  
Storage Tanks ◽  
Rate Dependent

Stratified tank models are used to simulate thermal storage in applications such as residential or commercial hot-water storage tanks, chilled-water storage tanks, and solar thermal systems. The energy efficiency of these applications relates to the system components and the level of stratification maintained during various flow events in the tank. One-dimensional (1D) models are used in building energy simulations because of the short computation time but often do not include flow-rate dependent mixing. The accuracy of 1D models for plug flow, plug flow with axial conduction, and two convection eddy-diffusivity models were compared with experimental data sets for discharging a 50-gal residential tank and recharging the tank with hot water from an external hot-water source. A minimum and maximum relationship for the eddy diffusivity factor were found at Re <2100 and >10,000 for recirculation of hot water to the top of the tank and vertical tubes inletting cold water at the bottom. The root mean square error decreased from >4 °C to near 2 °C when considering flow-based mixing models during heating, while the exponential decay of the eddy diffusion results in a root mean square error reduction of 1 °C for cone-shaped diffusers that begin to relaminarize flow at the inlet.

Behavior of Unanchored Fluid-Filled Tanks Subjected to Ground Excitation

1988 ◽  
Vol 55 (3) ◽  
pp. 654-659 ◽  
Author(s):  
S. Natsiavas ◽  
C. D. Babcock
Keyword(s):  
Experimental Data ◽  
Dramatic Reduction ◽  
Base Excitation ◽  
Storage Tanks ◽  
Response Frequency ◽  
Qualitative And Quantitative ◽  
Liquid Storage ◽  
Beam Type ◽  
Effective Beam ◽  
Good Agreement

An analysis developed for the response of liquid storage tanks under horizontal base excitation is employed and numerical results are obtained for unanchored tanks. These results are compared and found to be in good agreement with experimental data. Base uplift is shown to cause a dramatic reduction in the effective beam-type stiffness of a tank, which in turn reduces the tank response frequency and changes the developed hydrodynamic loads significantly. Based on these results, an explanation is provided for some great qualitative and quantitative differences in the behavior of a tank, resulting from its base fixity condition alone.

Damage observations and remedial options for approximately 1500 legged and flat-based liquid storage tanks following the 2016 Kaikōura earthquake

Structures ◽  
2020 ◽  
Vol 24 ◽  
pp. 357-376 ◽  
Author(s):  
Mohsen Yazdanian ◽  
Jason M. Ingham ◽  
Will Lomax ◽  
Regan Wood ◽  
Dmytro Dizhur
Keyword(s):  
Storage Tanks ◽  
Liquid Storage ◽  
Kaikoura Earthquake

scholarly journals Theoretical Insight into the Reversal of Chemoselectivity in Diels-Alder Reactions of α,β-Unsaturated Aldehydes and Ketones Catalyzed by Brønsted and Lewis Acids

Organics ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 38-49
Author(s):  
Lakhdar Benhamed ◽  
Sidi Mohamed Mekelleche ◽  
Wafaa Benchouk
Keyword(s):  
Lewis Acids ◽  
Major Product ◽  
Diels Alder ◽  
Unsaturated Ketone ◽  
Unsaturated Aldehydes ◽  
Aldehydes And Ketones ◽  
Theoretical Insight ◽  
Insight Into ◽  
Good Agreement

Experimentally, a reversal of chemoselectivity has been observed in catalyzed Diels–Alder reactions of α,β-unsaturated aldehydes (e.g., (2E)-but-2-enal) and ketones (e.g., 2-hexen-4-one) with cyclopentadiene. Indeed, using the triflimidic Brønsted acid Tf2NH as catalyst, the reaction gave a Diels–Alder adduct derived from α,β-unsaturated ketone as a major product. On the other hand, the use of tris(pentafluorophenyl)borane B(C6F5)3 bulky Lewis acid as catalyst gave mainly the cycloadduct of α,β-unsaturated aldehyde as a major product. Our aim in the present work is to put in evidence the role of the catalyst in the reversal of the chemoselectivity of the catalyzed Diels–Alder reactions of (2E)-but-2-enal and 2-Hexen-4-one with cyclopentadiene. The calculations were performed at the ωB97XD/6-311G(d,p) level of theory and the solvent effects of dichloromethane were taken into account using the PCM solvation model. The obtained results are in good agreement with experimental outcomes.

scholarly journals The Effectiveness of Multi-Label Classification and Multi-Output Regression in Social Trait Recognition

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4127
Author(s):  
Will Farlessyost ◽  
Kelsey-Ryan Grant ◽  
Sara R. Davis ◽  
David Feil-Seifer ◽  
Emily M. Hand
Keyword(s):  
Social Interactions ◽  
First Impressions ◽  
Social Traits ◽  
Judicial Proceedings ◽  
Facial Attributes ◽  
Future Work ◽  
Automated Methods ◽  
Insight Into ◽  
Social Trait ◽  
Better Than

First impressions make up an integral part of our interactions with other humans by providing an instantaneous judgment of the trustworthiness, dominance and attractiveness of an individual prior to engaging in any other form of interaction. Unfortunately, this can lead to unintentional bias in situations that have serious consequences, whether it be in judicial proceedings, career advancement, or politics. The ability to automatically recognize social traits presents a number of highly useful applications: from minimizing bias in social interactions to providing insight into how our own facial attributes are interpreted by others. However, while first impressions are well-studied in the field of psychology, automated methods for predicting social traits are largely non-existent. In this work, we demonstrate the feasibility of two automated approaches—multi-label classification (MLC) and multi-output regression (MOR)—for first impression recognition from faces. We demonstrate that both approaches are able to predict social traits with better than chance accuracy, but there is still significant room for improvement. We evaluate ethical concerns and detail application areas for future work in this direction.

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