Advanced Dryout Correlation for BWR Fuel

2010 ◽  
Author(s):  
D. Paramonov ◽  
C. Adamsson
Keyword(s):  
Experimental Data ◽  
Regression Coefficients ◽  
Qualitative Behavior ◽  
Empirical Correlations ◽  
Operational Space ◽  
Power Profile ◽  
Fuel Design ◽  
New Form ◽  
Additional Value ◽  
Dry Out

Each BWR fuel design requires a method to predict its dryout performance in order to be licensed. Presently, the assessment of dry-out risk is based on empirical correlations, which sometimes results in inaccurate or non-physical predictions in certain portions of operational space. This poses a number of limitations as plant operators seek to extract additional value from the fuel through more aggressive operation strategies. A new form of BWR dryout correlation is developed. Accuracy of predictions outside of experimental data range is increased by employing a non-linear correlation form and the transformation to axial power profile, which is based on physical considerations. Proper qualitative behavior is assured by the correlation form itself rather than values of regression coefficients.

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.

Solubility of the Ketoconazole (an Antifungal Drug) in Supercritical Carbon Dioxide and Menthol as a Cosolvent (Ternary System): Experimental Data and Empirical Correlations

2021 ◽  
Author(s):  
Gholamhossein Sodeifian ◽  
Seyed Ali Sajadian ◽  
Fariba Razmimanesh ◽  
Seyed Mojtaba Hazaveie
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Binary System ◽  
Supercritical Carbon Dioxide ◽  
Ternary System ◽  
Drug Solubility ◽  
Analysis Method ◽  
Empirical Correlations ◽  
Semiempirical Models ◽  
Supercritical Carbon

Abstract One of the main steps in choosing the drug nanoparticle production processes by supercritical carbon dioxide (SC-CO2) is determining the solubility of the solid solute. For this purpose, the solubility of Ketoconazole (KTZ) in the SC-CO2, binary system, as well as in the SC-CO2-menthol (cosolvent), ternary system, was measured at 308–338 K and 12–30 MPa using the static analysis method. The KTZ solubility in the SC-CO2 ranged between 1.70×10− 6 and 8.02×10− 4, while drug solubility in the SC-CO2 with cosolvent varied from 2.7×10− 5 to 1.96×10− 4. This difference indicated the significant effect of menthol cosolvent on KTZ solubility in the SC-CO2. Moreover, KTZ solubilities in the two systems were correlated by several empirical and semiempirical models. Among them, Sodeifian et al., Bian et al., MST, and Bartle et al. models can more accurately correlate experimental data for the binary system than other used models. Also, the Sodeifian and Sajadian model well fitted the solubility data of the ternary system with AARD,%= 6.45, Radj= 0.995.

scholarly journals Study of Refractive Indices and Its Theories for Mixtures of N, N-Diethylethanamine and Acetates

2020 ◽  
Vol 12 (3) ◽  
pp. 363-370
Author(s):  
P. Tyagi ◽  
K. Kumar ◽  
M. Rani ◽  
N. Sabharwal
Keyword(s):  
Experimental Data ◽  
Methyl Acetate ◽  
Butyl Acetate ◽  
Composition Range ◽  
Polynomial Equation ◽  
Carbon Chain ◽  
Refractive Indices ◽  
Carbon Chain Length ◽  
Propyl Acetate ◽  
Empirical Correlations

This paper reports the refractive indices ( ) of N,N-diethylethanamine + methyl acetate, ethyl acetate, propyl acetate, butyl acetate and pentyl acetate at 298.15 K and at different composition range. The various empirical correlations like Arago-Biot (AB), Gladstone-Dale (GD), Lorentz-Lorenz (L-L) Heller (H), Weiner (W), Newton (Nw) and Erying-John (E-J) were applied to experimental data for estimating theoretical value of refractive indices. For an equimolar mixture, the predicted deviation in refractive index values is consistent well with the experimental data. It has been found that the interactions between amine and different esters decrease when carbon chain length in ester increases. Also refractive indices are affected with change in temperature. To evaluate the standard deviation, RK polynomial equation was fitted to the measured refractive indices data.

Calculation of Polymer Flow Using Micro-Macro Simulations

2004 ◽  
Author(s):  
Kathleen Feigl ◽  
Deepthika C. Senaratne
Keyword(s):  
Experimental Data ◽  
Evolution Equations ◽  
Qualitative Behavior ◽  
Simulation Techniques ◽  
Pressure Fields ◽  
Model Dynamics ◽  
Polymer Configurations ◽  
Gaussian Stochastic Processes ◽  
Reptation Theory ◽  
Compute Velocity

A micro-macro simulation algorithm for the calculation of polymeric flow is developed and implemented. The algorithm couples standard finite element techniques to compute velocity and pressure fields with stochastic simulation techniques to compute polymer stress from simulated polymer dynamics. The polymer stress is computed using a microscopic-based rheological model which combines aspects of network and reptation theory with aspects of continuum mechanics. The model dynamics include two Gaussian stochastic processes each of which is destroyed and regenerated according to a survival time randomly generated from the material’s relaxation spectrum. The Eulerian form of the evolution equations for the polymer configurations are spatially discretized using the discontinuous Galerkin method. The algorithm is tested on benchmark contraction domains for a polyisobutylene (PIB) solution. In particular, the flow in the abrupt die entry domain is simulated and the simulation results are compared with experimental data. The results exhibit the correct qualitative behavior of the polymer and agree well with the experimental data.

Theoretical Prediction of Onset of Horizontal Slug Flow

1980 ◽  
Vol 102 (4) ◽  
pp. 441-445 ◽  
Author(s):  
Kaichiro Mishima ◽  
Mamoru Ishii
Keyword(s):  
Experimental Data ◽  
Stability Analysis ◽  
Slug Flow ◽  
Flow Analysis ◽  
Finite Amplitude ◽  
Empirical Correlations ◽  
Deformation Limit ◽  
Theoretical Criterion ◽  
The Stability ◽  
Good Agreement

A criterion for the onset of a slug flow in a horizontal duct is derived theoretically. A potential flow analysis is carried out by considering waves of finite amplitude. The stability criterion is obtained by introducing the wave deformation limit and the “most dangerous wave” concept in the stability analysis. The present theoretical criterion for slug formation shows very good agreement with a large number of experimental data and with some empirical correlations.

scholarly journals On a new form of reagent against perspiration effects on shoe materials

1945 ◽  
Vol 44 (1) ◽  
pp. 53-55 ◽  
Author(s):  
A. Colin-Russ
Keyword(s):  
Salt Solution ◽  
Room Temperature ◽  
Ammonium Acetate ◽  
Common Salt ◽  
Cotton Yarn ◽  
Precise Data ◽  
White Cotton ◽  
New Form ◽  
Dry Out ◽  
Aqueous Ammonium Acetate

In a discussion of a series of tests connected with the fastness of colours on textile fibres, Villavecchia (1918) mentions the use of neutral ammonium acetate or common salt solution for measuring the colour resistance to perspiration. Thus in the case of coloured cotton, this is immersed for 10 min. alongside an equal quantity of white cotton yarn in a 0·1% aqueous ammonium acetate at 80°C., and the extent of colouring of the yarn as well as the degree of stripping of the coloured sample noted after drying without rinsing. An odd number of degrees of fastness is arbitrarily assigned to the coloured specimen according to the result, e.g. V degrees if neither the original tint nor the whiteness of the yarn is changed. Similarly with linen, hemp and ramie. For coloured wool both methods are used, viz. with sodium chloride and with ammonium acetate. In the former case, the alteration in colour is noted after simply dipping the wool in salt solution and allowing to air-dry out at room temperature. In the latter case, an equal quantity of white zephyr wool in addition to the white cotton is present. V degrees in all cases are stated to be conventionally adopted between industrial associations and dyestuff manufacturers for materials which are fast enough to reveal no change whatever in the testing bath. For coloured silk there are no precise data, and usually it is immersed in distilled water for several days to ascertain if any colour is lost.

Inlet Losses in Counterflow Wet-Cooling Towers

2001 ◽  
Vol 123 (2) ◽  
pp. 460-464 ◽  
Author(s):  
E. de Villiers ◽  
D. G. Kro¨ger
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Numerical Model ◽  
Loss Coefficient ◽  
Cooling Towers ◽  
Empirical Correlations ◽  
Dependent Variables ◽  
Loss Coefficients

The inlet loss coefficients for dry, isotropically packed, circular and rectangular counterflow cooling towers are determined experimentally and empirical correlations are formulated to fit this data. Computational fluid dynamics is used to investigate the dependence of the inlet loss coefficient on the rain zone characteristics. The rain zone generally dampens the inlet loss, but the coupling is indirect and involves a large number of dependent variables. The numerical model is validated by means of experimental data for dry towers and it is found that the degree of accuracy achieved for circular towers exceeds that for rectangular towers. Consequently, the correlation derived to predict this occurrence for circular towers can be applied more confidently than its rectangular counterpart.

A New Correlation for Heat Transfer Coefficient Prediction of Supercritical Pressure Water Flowing in Vertical Upward Tubes

2016 ◽  
Author(s):  
Xiangfei Kong ◽  
Huixiong Li ◽  
Changjiang Liao ◽  
Xianliang Lei ◽  
Qian Zhang
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Supercritical Pressure ◽  
Good Prediction ◽  
Empirical Correlations ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
New Correlation ◽  
Pressure Water ◽  
Supercritical Pressure Water

Supercritical pressure water has been widely used in many industrial fields, such as fossil-fired power plants and nuclear reactors because mainly of its high thermal efficiencies. Although many empirical correlations for heat transfer coefficients of supercritical pressure water have been proposed by different authors based on different experimental data base, there exist remarkable discrepancies between the predicted heat transfer coefficients of different correlations under even the same condition. Heat transfer correlations with good prediction performance are of considerable significance for developing supercritical (ultra-supercritical) pressure boilers and SCWRs. In this paper, the experimental data (about 7389 experimental data points) and 30 existing empirical correlations for heat transfer of supercritical pressure water (SCW) flowing in vertical upward tubes are collected from the open literatures. Evaluations of the prediction performance of the existing correlations are conducted based on the collected experimental data, and a detailed multi-collinearity analysis has been made on different correction factors involved in the existing correlations, and then based on the collected experimental data, a new heat transfer correlation is developed for the supercritical pressure water flowing in vertical upward tubes under normal and enhanced heat transfer mode. Compared with the existing correlations, the new correlation exhibits good prediction accuracy, with a mean absolute deviation (MAD) of 9.63%.

scholarly journals Physico-chemical Properties of Solutions of Lithium Bis(fluorosulfonyl)imide (LiFSI) in Dimethyl Carbonate, Ethylene Carbonate, and Propylene Carbonate

2021 ◽  
Author(s):  
Johannes Neuhaus ◽  
Erik von Harbou ◽  
Hans Hasse
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Propylene Carbonate ◽  
Dimethyl Carbonate ◽  
Ethylene Carbonate ◽  
Chemical Properties ◽  
Lithium Ion ◽  
Solvent System ◽  
Empirical Correlations ◽  
Physico Chemical

Battery performance strongly depends on the choice of the electrolyte-solvent system. Lithium bis(fluorosulfonyl)imide (LiFSI) is a highly interesting novel electrolyte. Information on physico-chemical properties of solutions of LiFSI, however, is scarce. Therefore, the density, shear viscosity, and electrical conductivity of solutions of LiFSI in three pure solvents that are interesting for battery applications: dimethyl carbonate (DMC), ethylene carbonate (EC), and propylene carbonate (PC), were studied experimentally at temperatures between 273 K and 333 K at 1 bar and concentrations of LiFSI up to 0.45 mol mol−1 in the present work. Empirical correlations of the experimental data are provided. The comparison of the data of this work with the corresponding LiPF6 data underpins the attractiveness of LiFSI as an electrolyte in lithium ion batteries.

scholarly journals Comparison of k-ε Models in Predicting Heat Transfer and Skin Friction Under High Free Stream Turbulence

1996 ◽  
Author(s):  
Ganesh R. Iyer ◽  
Savash Yavuzkurt
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Boundary Layer ◽  
Skin Friction ◽  
Turbulence Intensity ◽  
Free Stream ◽  
Skin Friction Coefficient ◽  
Empirical Correlations ◽  
Free Stream Turbulence ◽  
Boundary Layer Equations

Calculations of the effects of high free stream turbulence (FST) on heat transfer and skin friction in a flat plate turbulent boundary layer using different k-ε models (Launder-Sharma, K-Y Chien, Lam-Bremhorsi and Jones-Launder) are presented. This study was carried out in order to investigate the prediction capabilities of these models under high FST conditions. In doing so, TEXSTAN, a partial differential equation solver which is based on the ideas of Patankar and Spalding and solves steady-flow boundary layer equations, was used. Firstly, these models were compared as to how they predicted very low FST (≤ 1% turbulence intensity) cases. These baseline cases were tested by comparing predictions with both experimental data and empirical correlations. Then, these models were used in order to determine the effect of high FST (>5% turbulence intensity) on heat transfer and skin friction and compared with experimental data. Predictions for heat transfer and skin friction coefficient for all the turbulence intensities tested by all the models agreed well (within 1–8%) with experimental data. However, all these models predicted poorly the dissipation of turbulent kinetic energy (TKE) in the free stream and TKE profiles. Physical reasoning as to why the aforementioned models differ in their predictions and the probable cause of poor prediction of free-stream TKE and TKE profiles are given.

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