The Messina Straits tsunami of December 28, 1908: a critical review of experimental data and observations

1983 ◽  
Vol 6 (4) ◽  
pp. 429-442 ◽  
Author(s):  
S. Tinti ◽  
D. Giuliani
Keyword(s):  
Experimental Data ◽  
Critical Review

A Critical Review of NOx Correlations for Gas Turbine Combustors

1975 ◽  
Author(s):  
D. A. Sullivan ◽  
P. A. Mas
Keyword(s):  
Experimental Data ◽  
Data Base ◽  
Gas Turbine ◽  
Critical Review ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Empirical Correlations ◽  
Gas Turbine Combustors ◽  
Semi Empirical ◽  
Adequate Data

The effect of inlet temperature, pressure, air flowrate and fuel-to-air ratio on NOx emissions from gas turbine combustors has received considerable attention in recent years. A number of semi-empirical and empirical correlations relating these variables to NOx emissions have appeared in the literature. They differ both in fundamental assumptions and in their predictions. In the present work, these simple NOx correlations are compared to each other and to experimental data. A review of existing experimental data shows that an adequate data base does not exist to evaluate properly the various NOx correlations. Recommendations are proposed to resolve this problem in the future.

A Critical Review on the Determination of Pressure Drop During Condensation in Smooth and Enhanced Tubes

2013 ◽  
Author(s):  
Ahmet Selim Dalkiliç ◽  
Ali Celen ◽  
Mohamed M. Awad ◽  
Somchai Wongwises
Keyword(s):  
Neural Network ◽  
Heat Transfer ◽  
Experimental Data ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Critical Review ◽  
Heat Exchangers ◽  
Numerical Analyses ◽  
Enhanced Tubes

Heat exchangers using in-tube condensation have great significance in the refrigeration, automotive and process industries. Effective heat exchangers have been rapidly developed due to the demand for more compact systems, higher energy efficiency, lower material costs and other economic incentives. Enhanced surfaces, displaced enhancement devices, swirl-flow devices and surface tension devices improve the heat transfer coefficients in these heat exchangers. This study is a critical review on the determination of the condensation heat transfer coefficient of pure refrigerants flowing in vertical and horizontal tubes. The authors’ previous publications on this issue, including the experimental, theoretical and numerical analyses are summarized here. The lengths of the vertical and horizontal test sections varied between 0.5 m and 4 m countercurrent flow double-tube heat exchangers with refrigerant flowing in the inner tube and cooling water flowing in the annulus. The measured data are compared to theoretical and numerical predictions based on the solution of the artificial intelligence methods and CFD analyses for the condensation process in the smooth and enhanced tubes. The theoretical solutions are related to the design of double tube heat exchangers in refrigeration, air conditioning and heat pump applications. Detailed information on the in-tube condensation studies of heat transfer coefficient in the literature is given. A genetic algorithm (GA), various artificial neural network models (ANN) such as multilayer perceptron (MLP), radial basis networks (RBFN), generalized regression neural network (GRNN), and adaptive neuro-fuzzy inference system (ANFIS), and various optimization techniques such as unconstrained nonlinear minimization algorithm-Nelder-Mead method (NM), non-linear least squares error method (NLS), and Ansys CFD program are used in the numerical solutions. It is shown that the convective heat transfer coefficient of laminar and turbulent condensing film flows can be predicted by means of theoretical and numerical analyses reasonably well if there is a sufficient amount of reliable experimental data. Regression analysis gave convincing correlations, and the most suitable coefficients of the proposed correlations are depicted as compatible with the large number of experimental data by means of the computational numerical methods.

Simulation of Passing Vessel Effects on Moored Vessel Mooring Response due to Environmental Loads

2017 ◽  
Author(s):  
Nandhini Vasudevan ◽  
S. Nallayarasu
Keyword(s):  
Experimental Data ◽  
Critical Review ◽  
Separation Distance ◽  
Mooring Line ◽  
Review Of Literature ◽  
Limited Data ◽  
Mooring Lines ◽  
Comprehensive Review ◽  
Environmental Loads ◽  
Mooring Forces

A critical review of literature on the mooring forces on the berthed ship together with the passing vessel effects indicates limited data, thus requiring additional studies. Four methods have been found in the literature namely (a) Seelig’s, (b) Flory’s, (c) Kreibel’s, and (d) Modified Seelig’s methods. A comprehensive review and comparison of existing methods has been carried out to verify the applicability of each method to certain conditions and also to establish the parameters for study. It has been found that displacement of the vessels, separation distance between the vessels and velocity of the passing vessel greatly influence the passing vessel forces on moored ship. The software OPTIMOOR has been used to verify Flory’s and Seelig’s methods with the experimental data of Remery and also to study the combined effect of environmental loads and passing vessel effects on mooring lines. The results indicate that the interaction of waves and passing vessel effects are too onerous. Conclusions have been arrived based on the results that for separation distance of 100 m or less between vessels has a greater influence on mooring line forces, leading to breakage of lines.

A Critical Review on the Determination of Convective Heat Transfer Coefficient During Condensation in Smooth and Enhanced Tubes

2013 ◽  
Author(s):  
Ahmet Selim Dalkiliç ◽  
Ali Celen ◽  
Mohamed M. Awad ◽  
Somchai Wongwises
Keyword(s):  
Neural Network ◽  
Heat Transfer ◽  
Experimental Data ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Critical Review ◽  
Heat Exchangers ◽  
Convective Heat Transfer Coefficient ◽  
Enhanced Tubes

Heat exchangers using in-tube condensation have great significance in the refrigeration, automotive and process industries. Effective heat exchangers have been rapidly developed due to the demand for more compact systems, higher energy efficiency, lower material costs and other economic incentives. Enhanced surfaces, displaced enhancement devices, swirl-flow devices and surface tension devices improve the heat transfer coefficients in these heat exchangers. This study is a critical review on the determination of the condensation heat transfer coefficient of pure refrigerants flowing in vertical and horizontal tubes. The authors’ previous publications on this issue, including the experimental, theoretical and numerical analyses are summarized here. The lengths of the vertical and horizontal test sections varied between 0.5 m and 4 m countercurrent flow double-tube heat exchangers with refrigerant flowing in the inner tube and cooling water flowing in the annulus. The measured data are compared to theoretical and numerical predictions based on the solution of the artificial intelligence methods and CFD analyses for the condensation process in the smooth and enhanced tubes. The theoretical solutions are related to the design of double tube heat exchangers in refrigeration, air conditioning and heat pump applications. Detailed information on the in-tube condensation studies of heat transfer coefficient in the literature is given. A genetic algorithm (GA), various artificial neural network models (ANN) such as multilayer perceptron (MLP), radial basis networks (RBFN), generalized regression neural network (GRNN), and adaptive neuro-fuzzy inference system (ANFIS), and various optimization techniques such as unconstrained nonlinear minimization algorithm-Nelder-Mead method (NM), non-linear least squares error method (NLS), and Ansys CFD program are used in the numerical solutions. It is shown that the convective heat transfer coefficient of laminar and turbulent condensing film flows can be predicted by means of theoretical and numerical analyses reasonably well if there is a sufficient amount of reliable experimental data. Regression analysis gave convincing correlations, and the most suitable coefficients of the proposed correlations are depicted as compatible with the large number of experimental data by means of the computational numerical methods.

scholarly journals A Momentum Integral Method to Predict the Frictional Torque of a Rotating Disk With Protruding Bolts

1998 ◽  
Author(s):  
W. Gärtner
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Integral Equations ◽  
Critical Review ◽  
Integral Method ◽  
Rotating Disk ◽  
Frictional Torque ◽  
Momentum Integral ◽  
Good Agreement

A momentum integral method was developed to predict the frictional torque of a disk rotating in quiescent air with cylindrical protrusions mounted on its surface. The predicted torque is compared to experimental data taken for the protrusions placed on two different radii on the disk with two different numbers of protrusions on each radius. A critical review of the calculated results reveals that caused by the protrusions the predicted thickness of the boundary layer on the disk is of the same magnitude as the radius of the disk. Since in this case Prandtl’s simplifications for the boundary layer on which the momentum integral equations are based upon are not valid their use appears to be doubtful. However, the predicted frictional torque is in good agreement with the measurements for all configurations tested except for that with the smallest circumferential distance between the protrusions where the torque is overpredicted by the method. The application of the method for a disk rotating in a stationary housing is briefly discussed.

A Critical Review on the Numerical Methods of Two-Phase Flows

2012 ◽  
Author(s):  
Muhammet Balcilar ◽  
Ahmet Selim Dalkiliç ◽  
Ali Çelen ◽  
Nurullah Kayaci ◽  
Somchai Wongwises
Keyword(s):  
Neural Network ◽  
Heat Transfer ◽  
Experimental Data ◽  
Numerical Methods ◽  
Critical Review ◽  
Optimization Techniques ◽  
Numerical Analyses ◽  
Heat Transfer Characteristics ◽  
Two Phase ◽  
Transfer Characteristics

The two-phase flow processes play a significant role in the heat transfer processes in the chemical and power industry, including in nuclear power plants. This study is a critical review on the determination of the heat transfer characteristics of pure refrigerants flowing in vertical and horizontal tubes. The authors’ previous publications on this issue, including the numerical analyses, are summarized here. The lengths of the vertical and horizontal test sections varied between 0.5 m and 4 m countercurrent flow double-tube heat exchangers with refrigerant flowing in the inner tube and cooling water flowing in the annulus. The measured data are compared to numerical predictions based on the solution of the artificial intelligence methods and CFD analyses for the condensation and evaporation processes in the smooth and enhanced tubes. The theoretical solutions are related to the design of passive containment cooling systems (PCCS) in simplified water boiling reactors (SWBR). A genetic algorithm (GA), various artificial neural network models (ANN) such as multilayer perceptron (MLP), radial basis networks (RBFN), generalized regression neural network (GRNN), and adaptive neuro-fuzzy inference system (ANFIS), and various optimization techniques such as unconstrained nonlinear minimization algorithm-Nelder-Mead method (NM), non-linear least squares error method (NLS), and Fluent CFD program are used in the numerical solution. It is shown that the heat transfer characteristics of laminar and turbulent condensing and evaporating film flows such as heat transfer coefficient and pressure drop can be predicted by means of numerical analyses reasonably well if there is a sufficient amount of reliable experimental data. Regression analysis gave convincing correlations, and the most suitable coefficients of the proposed correlations are depicted as compatible with the large number of experimental data by means of the computational numerical methods. Dependency of the output of the ANNs from various numbers of input values is also shown for condensing and evaporating flows.

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