Evaluation of lightning-induced overvoltages on a distribution system: Validation of a dedicated code using experimental results on a reduced-scale model

2017 ◽  
Author(s):  
Massimo Brignone ◽  
Erica Ginnante ◽  
Daniele Mestriner ◽  
Laria Ruggi ◽  
Renato Procopio ◽  
...  
Keyword(s):  
Distribution System ◽  
Experimental Results ◽  
Scale Model ◽  
System Validation ◽  
Reduced Scale

Simulation of a Free Standing Riser Model and Validation With Experimental Results

2014 ◽  
Author(s):  
Marcio Yamamoto ◽  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Tomo Fujiwara ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Previous Experiment ◽  
Numerical Results ◽  
Experimental Results ◽  
Previous Article ◽  
Scale Model ◽  
Analysis Software ◽  
Free Standing ◽  
Reduced Scale

In this article, we present the numerical analysis of a Free Standing Riser. The numerical simulation was carried out using a commercial riser analysis software suit. The numerical model’s dimensions were the same of a 1/70 reduced scale model deployed in a previous experiment. The numerical results were compared with experimental results presented in a previous article [1]. Discussion about the model and limitations of the numerical analysis is included.

Physical modelling of an upflow anaerobic sludge blanket reactor: near-field study

2002 ◽  
Vol 45 (10) ◽  
pp. 157-162
Author(s):  
J.R. Gimenez ◽  
S.C. Nassr ◽  
R.D. Maestri ◽  
L.O. Monteggia
Keyword(s):  
Distribution System ◽  
Near Field ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Upflow Anaerobic Sludge Blanket ◽  
Scale Model ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Anaerobic Sludge Blanket ◽  
Reduced Scale

This paper presents a physical evaluation of an upflow anaerobic sludge blanket reactor. Specifically, the study contemplates the region influenced by the wastewater inlet jets at the bottom of the reactor, here termed the near-field area. A three-dimensional physical model of a UASB reactor in reduced scale, geometrically and dynamically correlated to a full-scale prototype was used in the evaluation. From the analysis of the major forces acting and of the physical properties investigated in the prototype, it was possible to establish non-dimensional relations that were applied to the reduced scale model, allowing the investigation of the phenomenon of interest. Tests were developed on the model to visualise the inlet flows under the buoyant effect at the bottom of the reactor, through the injection of a tracer fluid in the area with higher density, simulating the effects of the sludge bed. Based on the experimental results, it was possible to provide dimensioning criteria for the jet distribution system in UASB reactors.

Structural Analysis for a Reduced Scale Model of a Hydropower Plant Debris Containment Grid

2017 ◽  
Author(s):  
Felipe Santos de Castro ◽  
Eduardo Tadashi Katsuno ◽  
Andre Mitsuo Kogishi ◽  
José Marcos Paz de Souza ◽  
Joao Lucas Dozzi Dantas Dantas
Keyword(s):  
Structural Analysis ◽  
Hydropower Plant ◽  
Scale Model ◽  
Plant Debris ◽  
Reduced Scale

scholarly journals Economic design of alternative system to reduce the water distribution losses for sustainability

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
H. J. Surendra ◽  
B. T. Suresh ◽  
T. D. Ullas ◽  
T. Vinayak ◽  
Vinay P. Hegde
Keyword(s):  
Cost Estimation ◽  
Distribution System ◽  
Water Distribution ◽  
Preventive Measures ◽  
Scale Model ◽  
Microsoft Excel ◽  
Water Losses ◽  
Population Forecasting ◽  
Water Companies ◽  
Materials Used

AbstractWater companies and their consumers affected with leakages in water distribution system worldwide. This has attracted many practitioner’s attention as well as researchers over the past years. Selected study area suffers from water losses of about 10 to 15% which accounts to loss of about 9 to 9.75 million liters per month. The present study was under taken to understand, analyze and evaluate the losses and suggest preventive measures of wrapping and repair clamping for control of these losses. The assessment of water losses is done through comparative analysis of data using Microsoft Excel software. Population forecasting is done in context of assessing the amount of water lost that can be prevented in future decades, adjusting to increased water demand and losses. For better efficiency of the suggested methods, experimental analysis was carried out on a reduced scale model of a single stretched pipeline. Cost estimation of the preventive measures was done by obtaining information about the materials used by trading professionals.

scholarly journals A parametric prediction of the Young’s modulus of polymers enhanced with ΜWCNTs

2018 ◽  
Vol 233 ◽  
pp. 00025
Author(s):  
P.V. Polydoropoulou ◽  
K.I. Tserpes ◽  
Sp.G. Pantelakis ◽  
Ch.V. Katsiropoulos
Keyword(s):  
Young’S Modulus ◽  
Elastic Properties ◽  
Young's Modulus ◽  
Experimental Results ◽  
Scale Model ◽  
Fe Model ◽  
Multi Scale ◽  
Unit Cells ◽  
Random Dispersion

In this work a multi-scale model simulating the effect of the dispersion, the waviness as well as the agglomerations of MWCNTs on the Young’s modulus of a polymer enhanced with 0.4% MWCNTs (v/v) has been developed. Representative Unit Cells (RUCs) have been employed for the determination of the homogenized elastic properties of the MWCNT/polymer. The elastic properties computed by the RUCs were assigned to the Finite Element (FE) model of a tension specimen which was used to predict the Young’s modulus of the enhanced material. Furthermore, a comparison with experimental results obtained by tensile testing according to ASTM 638 has been made. The results show a remarkable decrease of the Young’s modulus for the polymer enhanced with aligned MWCNTs due to the increase of the CNT agglomerations. On the other hand, slight differences on the Young’s modulus have been observed for the material enhanced with randomly-oriented MWCNTs by the increase of the MWCNTs agglomerations, which might be attributed to the low concentration of the MWCNTs into the polymer. Moreover, the increase of the MWCNTs waviness led to a significant decrease of the Young’s modulus of the polymer enhanced with aligned MWCNTs. The experimental results in terms of the Young’s modulus are predicted well by assuming a random dispersion of MWCNTs into the polymer.

Wave Energy Hyperbaric Device for Electricity Production

2007 ◽  
Author(s):  
Segen F. Estefen ◽  
Paulo Roberto da Costa ◽  
Eliab Ricarte ◽  
Marcelo M. Pinheiro
Keyword(s):  
Power Generation ◽  
Wave Energy ◽  
Experimental Results ◽  
Electricity Production ◽  
Scale Model ◽  
Small Scale ◽  
Regular Waves ◽  
Hyperbaric Chamber ◽  
Small Scale Model

Wave energy is a renewable and non-polluting source and its use is being studied in different countries. The paper presents an overview on the harnessing of energy from waves and the activities associated with setting up a plant for extracting energy from waves in Port of Pecem, on the coast of Ceara State, Brazil. The technology employed is based on storing water under pressure in a hyperbaric chamber, from which a controlled jet of water drives a standard turbine. The wave resource at the proposed location is presented in terms of statistics data obtained from previous monitoring. The device components are described and small scale model tested under regular waves representatives of the installation region. Based on the experimental results values of prescribed pressures are identified in order to optimize the power generation.

Validating Numerical CFD Simulations With Experimental Data for Turbulence Phenomena in Axial Flow Gas Turbine Diffusers

2009 ◽  
Author(s):  
Farrokh Zarifi-Rad ◽  
Hamid Vajihollahi ◽  
James O’Brien
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Axial Flow ◽  
Experimental Results ◽  
Scale Model ◽  
Data Set ◽  
Pressure Profiles ◽  
Scale Models ◽  
Inlet Conditions

Scale models give engineers an excellent understanding of the aerodynamic behavior behind their design; nevertheless, scale models are time consuming and expensive. Therefore computer simulations such as Computational Fluid Dynamics (CFD) are an excellent alternative to scale models. One must ask the question, how close are the CFD results to the actual fluid behavior of the scale model? In order to answer this question the engineering team investigated the performance of a large industrial Gas Turbine (GT) exhaust diffuser scale model with performance predicted by commercially available CFD software. The experimental results were obtained from a 1:12 scale model of a GT exhaust diffuser with a fixed row of blades to simulate the swirl generated by the last row of turbine blades five blade configurations. This work is to validate the effect of the turbulent inlet conditions on an axial diffuser, both on the experimental front and on the numerical analysis approach. The object of this work is to bring forward a better understanding of velocity and static pressure profiles along the gas turbine diffusers and to provide an accurate experimental data set to validate the CFD prediction. For the CFD aspect, ANSYS CFX software was chosen as the solver. Two different types of mesh (hexagonal and tetrahedral) will be compared to the experimental results. It is understood that hexagonal (HEX) meshes are more time consuming and more computationally demanding, they are less prone to mesh sensitivity and have the tendancy to converge at a faster rate than the tetrahedral (TET) mesh. It was found that the HEX mesh was able to generate more consistent results and had less error than TET mesh.

A Study of Aspiration Effects in Reduced-Scale Model Airbag Modules

1998 ◽  
Author(s):  
Y. G. Lee ◽  
C. S. Yu ◽  
P. W. Green ◽  
L.-D. Chen ◽  
P. B. Butler
Keyword(s):  
Scale Model ◽  
Reduced Scale

Reduced Model Device of Solutions to Control Thermal Buckling Effects in HP-HT Subsea Pipelines

2008 ◽  
Author(s):  
Helio C. Silva-Junior ◽  
Carlos O. Cardoso ◽  
Marco A. P. Carmignotto ◽  
Jose C. Zanutto
Keyword(s):  
Imaging Technique ◽  
Thermal Buckling ◽  
Scale Model ◽  
Reduced Model ◽  
Safe Operation ◽  
High Pressure And Temperature ◽  
Model Geometry ◽  
Subsea Pipelines ◽  
Model Device ◽  
Reduced Scale

Nowadays, the safe operation of HP-HT subsea pipelines resting on seabed must take into account the thermal buckling phenomenon. The transport of oil with high pressure and temperature can cause uncontrolled thermal buckling in subsea pipelines. The failure risk must be carefully evaluated to design the pipeline with safety. Nowadays to control the thermal buckling the use of man made triggers is seen like the best solution for cost and safety of subsea pipelines. Some projects employ man-made triggers to control the thermal buckling in the last years around the world. In this article is presented the system and methodology used to test some solutions in a reduced scale model. Different geometric setups along the model line were tested. Solutions like sleepers, dual sleepers and buoyancy were tested and the geometric and structural behavior monitored. The reduced model has 195 m length, and was developed in the IPT Towing Tank, representing a pipeline section of almost 6 km long. Strains, temperature, pressure and displacements were measured in several sections of the model. Additionally, an imaging technique for the model geometry retrieval was developed. This paper presents the experimental setup developed to investigate the performance of man-made triggers solutions for HP-HT subsea pipelines.

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