scholarly journals The Rough Model Method (RMM) Application to The Computation of Normal Depth in Circular Conduit

2014 ◽  
Vol 8 (1) ◽  
pp. 57-63
Author(s):  
Bachir Achour ◽  
Sabah Sehtal
Keyword(s):  
Turbulent Flow ◽  
Correction Factor ◽  
Linear Dimension ◽  
New Method ◽  
Entire Domain ◽  
Model Method ◽  
Rough Model ◽  
The Relationship

A new method is presented to compute the normal depth in circular conduit. This is the rough model method (RMM). It states that the linear dimension of a conduit or channel is equal to the linear dimension of a referential rough model corrected by the effect of a non-dimensional correction factor. The method is based on the Colebrook-White and Darcy-Weisbach relationships, applicable to the entire domain of turbulent flow. From the relationship governing the flow in the rough model, the normal depth in a circular conduit is explicitly deduced.

Design of a Pressurized Trapezoidal Shaped Conduit Using the Rough Model Method (Part 1)

2014 ◽  
Vol 945-949 ◽  
pp. 892-898
Author(s):  
Bachir Achour ◽  
Mohammed Riabi
Keyword(s):  
Hydraulic Engineer ◽  
Turbulent Flow ◽  
Correction Factor ◽  
Complex Problem ◽  
Explicit Calculation ◽  
Hydraulic Characteristics ◽  
Entire Domain ◽  
Model Method ◽  
Linear Dimensions ◽  
Rough Model

Through the Rough Model Method (RMM) an explicit calculation is proposed to solve the complex problem of the design of a pressurized trapezoidal shaped conduit characterized by three linear dimensions. Firstly, the method is applied to a rough model of the same shape in order to establish the equations governing its geometric and hydraulic characteristics. These equations are then secondly used to easily deduce the required linear dimensions of the current conduit by introducing a non-dimensional correction factor. The application of the obtained relationships requires only a strict minimum of data. All relationships provided in this article are applicable to the entire domain of the turbulent flow. Practical examples are taken to enable the hydraulic engineer to better understanding the advocated method and to observe the facility with which design of such a geometric profile can be performed.

Design of a Pressurized Trapezoidal Shaped Conduit Using the Rough Model Method (Part 2)

2014 ◽  
Vol 580-583 ◽  
pp. 1828-1841 ◽  
Author(s):  
Bachir Achour ◽  
Ali Bedjaoui
Keyword(s):  
Hydraulic Engineer ◽  
Turbulent Flow ◽  
Correction Factor ◽  
Complex Problem ◽  
Explicit Calculation ◽  
Hydraulic Characteristics ◽  
Entire Domain ◽  
Model Method ◽  
Linear Dimensions ◽  
Rough Model

Through the Rough Model Method (RMM) an explicit calculation is proposed to solve the complex problem of the design of a pressurized trapezoidal shaped conduit characterized by three linear dimensions. Firstly, the method is applied to a rough model of the same shape in order to establish the equations governing its geometric and hydraulic characteristics. These equations are then secondly used to easily deduce the required linear dimensions of the current conduit by introducing a non-dimensional correction factor. The application of the obtained relationships requires only a strict minimum of data. All relationships provided in this article are applicable to the entire domain of the turbulent flow. Practical examples are taken to enable the hydraulic engineer to better understanding the advocated method and to observe the facility with which design of such a geometric profile can be performed.

Computation of Normal Depth in Trapezoidal Open Channel Using the Rough Model Method

2014 ◽  
Vol 955-959 ◽  
pp. 3231-3237
Author(s):  
Bachir Achour
Keyword(s):  
Aspect Ratio ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Linear Dimension ◽  
Open Channel ◽  
Discharge Energy ◽  
Flow Discharge ◽  
Model Method ◽  
Rough Model ◽  
Depth Relationship

The recurring problem of calculating the normal depth in a trapezoidal open channel is easily solved by the rough model method. The Darcy-Weisbach relationship is applied to a referential rough model whose friction factor is arbitrarily chosen. This leads to establish the non-dimensional normal depth relationship in the rough model. Through a non-dimensional correction factor of linear dimension, the aspect ratio and therefore normal depth in the studied channel is deduced. Keywords: Rough model method, Trapezoidal channel, Normal depth, Turbulent flow, Discharge, Energy slope.

Design of a Pressurized Circular Pipe with Benches Using the Rough Model Method (RMM)

2014 ◽  
Vol 960-961 ◽  
pp. 586-591
Author(s):  
Mohammed Riabi ◽  
Bachir Achour
Keyword(s):  
Turbulent Flow ◽  
Friction Factor ◽  
Correction Factor ◽  
Relative Roughness ◽  
Model Method ◽  
Linear Dimensions ◽  
Rough Model ◽  
Current Design ◽  
Basic Equations ◽  
Geometric Elements

The rough model method (RMM) is explained through its application to the design of a pressurized circular shaped conduit with benches, widely used in practice. The three basic equations of turbulent flow are firstly applied to define explicitly the geometric elements of a referential rough model characterized by an arbitrary assigned relative roughness value. The required linear dimensions of the studied conduit are then easily deduced by multiplying the homologues linear dimensions of the rough model by a non-dimensional correction factor. Friction factor is not indispensable when applying the RMM, unlike current design methods. Resulting RMM equations are not only explicit but are also valid in the entire domain of turbulent flow.

Design of a Pressurized Rectangular-Shaped Conduit Using the Rough Model Method (Part 1)

2014 ◽  
Vol 641-642 ◽  
pp. 261-266
Author(s):  
Bachir Achour
Keyword(s):  
Hydraulic Engineer ◽  
Correction Factor ◽  
Linear Dimension ◽  
Second Step ◽  
Hydraulic Characteristics ◽  
Hyperbolic Functions ◽  
The Third ◽  
Model Method ◽  
Linear Dimensions ◽  
Rough Model

The rough model method is successfully used to design a pressurized rectangular shaped conduit characterized by two linear dimensions. In this study, the focus is on the calculation of the horizontal linear dimension of the conduit. In a first step, the method is applied to a referential rough model in order to establish the relationships that govern its hydraulic characteristics. The obtained equations are of the third degree and are easily solved by trigonometric and hyperbolic functions. In a second step, these equations are used to easily deduce the linear dimension sought by introducing a non-dimensional correction factor. Practical example is taken to enable the hydraulic engineer to better understanding the advocated method and to observe the facility with which design of such a geometric profile can be performed. The calculation uses a strict minimum of data measurable in practice, in particular the absolute roughness.

Computation of Normal Depth in Horseshoe Shaped Tunnel Using the Rough Model Method

2014 ◽  
Vol 1006-1007 ◽  
pp. 826-832
Author(s):  
Bachir Achour
Keyword(s):  
Significant Role ◽  
Correction Factor ◽  
Analytical Method ◽  
Open Channels ◽  
Second Step ◽  
Roughness Coefficient ◽  
Hydraulic Characteristics ◽  
Model Method ◽  
Rough Model ◽  
Measurable Parameter

Normal depth plays a significant role in the design of open channels and in the analysis of the non-uniform flow as well. Currently, there is no analytical method for calculation of the normal depth in open channels, including the horseshoe profile. Current methods are either iterative or approximate. They also consider, unreasonably, Chezy’s coefficient or Manning’s roughness coefficient as a given data of the problem, despite the fact that these coefficients depend on the normal depth sought. In this study, a new analytical method is presented for calculating the normal depth in a horseshoe shaped tunnel. The method takes into account, in particular, the effect of the absolute roughness which is a readily measurable parameter in practice. In a first step, the method is applied to a referential rough model in order to establish the relationships that govern its hydraulic characteristics. In a second step, these equations are used to easily deduce the required normal depth by introducing a non-dimensional correction factor. A practical example is considered to better explain the advocated method and to appreciate its simplicity and efficiency.

SOME OBSERVATIONS ON PREGNANEDIOL EXCRETION DURING THE NORMAL MENSTRUAL CYCLE

1957 ◽  
Vol 24 (3_Suppl) ◽  
pp. S207
Author(s):  
A. Klopper
Keyword(s):  
Menstrual Cycle ◽  
Corpus Luteum ◽  
New Method ◽  
Menstrual Bleeding ◽  
Normal Menstrual Cycle ◽  
The Relationship ◽  
New View

Abstract The changes in view on the significance and amount of urinary pregnanediol in the menstrual cycle are reviewed; in particular the effects of the discovery that the adrenals in both sexes normally contribute to the urinary pregnanediol. Pregnanediol excretion during the menstrual cycle was studied by means of a new method of assay (Klopper et al., 1955) and the results applied to present day concepts of the growth and duration of the corpus luteum. The relationship between pregnanediol excretion and ovulation or the onset of menstrual bleeding was studied. A new view is put forward on the influence of age and parity on the production of progesterone by the corpus luteum.

Document- and Keyword-based Author Co-citation Analysis

2018 ◽  
Vol 2 (2) ◽  
pp. 70-82 ◽  
Author(s):  
Binglu Wang ◽  
Yi Bu ◽  
Win-bin Huang
Keyword(s):  
Citation Analysis ◽  
Semantic Similarity ◽  
Method Validation ◽  
New Method ◽  
Global Network ◽  
Network Visualization ◽  
Knowledge Domain ◽  
Knowledge Domains ◽  
Domain Mapping ◽  
The Relationship

AbstractIn the field of scientometrics, the principal purpose for author co-citation analysis (ACA) is to map knowledge domains by quantifying the relationship between co-cited author pairs. However, traditional ACA has been criticized since its input is insufficiently informative by simply counting authors’ co-citation frequencies. To address this issue, this paper introduces a new method that reconstructs the raw co-citation matrices by regarding document unit counts and keywords of references, named as Document- and Keyword-Based Author Co-Citation Analysis (DKACA). Based on the traditional ACA, DKACA counted co-citation pairs by document units instead of authors from the global network perspective. Moreover, by incorporating the information of keywords from cited papers, DKACA captured their semantic similarity between co-cited papers. In the method validation part, we implemented network visualization and MDS measurement to evaluate the effectiveness of DKACA. Results suggest that the proposed DKACA method not only reveals more insights that are previously unknown but also improves the performance and accuracy of knowledge domain mapping, representing a new basis for further studies.

scholarly journals Analyzing and Visualizing Spatiotemporal Patterns of El Niño Teleconnections Using Attribute Trajectories

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 414
Author(s):  
Long Zhang ◽  
Bert Van Schaeybroeck ◽  
Steven Caluwaerts ◽  
Piet Termonia ◽  
Nico Van de Weghe
Keyword(s):  
Data Structures ◽  
El Niño ◽  
Temperature Increase ◽  
El Nino ◽  
Global Climate ◽  
Spatiotemporal Patterns ◽  
New Method ◽  
Anomalous Temperature ◽  
General Dynamics ◽  
The Relationship

El Niño influences the global climate through teleconnections that are not constant in space and time. In order to study and visualize the spatiotemporal patterns of the El Niño teleconnections, a new method inspired by the concept of attribute trajectories is proposed. The coordinates of the trajectories are the normalized anomalies of the relevant meteorological variables in El Niño. The data structures called flocks are extracted from the trajectories to indicate the regions that are subject to the same type of El Niño teleconnection for a certain period. It is then shown how these structures can be used to get a detailed, spatiotemporal picture of the dynamics of the El Niño teleconnections. The comparison between the flocks of the same temporal scale reveals the general dynamics of the teleconnection, while the analysis among the flocks of different temporal scales indicates the relationship between the coverage and their duration. As an illustration of this method, the spatiotemporal patterns of the anomalous temperature increase caused by El Niño are presented and discussed at the monthly and seasonal scales. This study demonstrates the capability of the proposed method in analyzing and visualizing the spatiotemporal patterns of the teleconnections.

scholarly journals On Newcomb's method of investigating periodicities and its application to Brückner's weather cycle

1914 ◽  
Vol 90 (619) ◽  
pp. 349-355
Keyword(s):  
Thermal Radiation ◽  
The Other ◽  
New Method ◽  
Critical Examination ◽  
Numerical Work ◽  
Average Value ◽  
Other Hand ◽  
Relationship Of ◽  
The Relationship ◽  
Great Simplicity

During the last few years of his life Prof. Simon Newcomb was keenly interested in the problem of periodicities, and devised a new method for their investigation. This method is explained, and to some extent applied, in a paper entitled "A Search for Fluctuations in the Sun's Thermal Radiation through their Influence on Terrestrial Temperature." The importance of the question justifies a critical examination of the relationship of the older methods to that of Newcomb, and though I do not agree with his contention that his process gives us more than can be obtained from Fourier's analysis, it has the advantage of great simplicity in its numerical work, and should prove useful in a certain, though I am afraid, very limited field. Let f ( t ) represent a function of a variable which we may take to be the time, and let the average value of the function be zero. Newcomb examines the sum of the series f ( t 1 ) f ( t 1 + τ) + f ( t 2 ) f ( t 2 + τ) + f ( t 3 ) f ( t 3 + τ) + ..., where t 1 , t 2 , etc., are definite values of the variable which are taken to lie at equal distances from each other. If the function be periodic so as to repeat itself after an interval τ, the products are all squares and each term is positive. If, on the other hand, the periodic time be 2τ, each product will be negative and the sum itself therefore negative. It is easy to see that if τ be varied continuously the sum of the series passes through maxima and minima, and the maxima will indicated the periodic time, or any of its multiples.

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