scholarly journals Variation of Coefficient of Friction and Friction Head Losses Along a Pipe with Multiple Outlets

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 844 ◽  
Author(s):  
Wissam H. Alawee ◽  
Yousef A. Almolhem ◽  
Badronnisa Yusuf ◽  
Thamer A. Mohammad ◽  
Hayder A. Dhahad
Keyword(s):  
Experimental Data ◽  
Coefficient Of Friction ◽  
Field Studies ◽  
Pipe Length ◽  
G Factor ◽  
Factors Affecting ◽  
Head Losses ◽  
Main Pipe ◽  
Supply Tank ◽  
The Coefficient Of Friction

The flow in a pipe having multiple outlets is considered as an advanced problem in hydraulic engineering; many discrepancies were found in the literature, in addition to the lack of experimental and field studies. The main goal of this study is to simulate the flow in a pipe with multiple outlets in order to examine the existing methodologies for estimation of the friction head losses, and to propose a methodology that is based on experimental data. The main physical model in this study consisted of a water supply tank, a pipe with multiple outlets having a piezometer at each outlet. Different pipe diameters were used in this study, the pipe diameters were 25.4 mm (1 in), 38.1 mm (1.5 in), 50.8 (2 in) and 76.2 mm (3 in). The inlet heads used were 1.7 m and 2.2 m. The data collected from different flow conditions were used to assess the variation in the coefficient of friction and friction head losses along the pipe length. It can be concluded that the spacing between any two successive outlets (S) and area ratio (AR = Area of outlet/Area of the main pipe) are the main factors affecting the friction head losses along the pipe. The ratio of total friction head losses along a pipe with outlets having the same properties (length (L), discharge (Q), diameter (d) and material) to a pipe without outlets and having the same properties is called the G factor. The G factor calculated using selected formulae was overestimated in comparison to the calculated G factor obtained from experimental data. For large values of S/d (spacing between outlets/diameter of main pipe), the difference between coefficient of friction in first segment (f1) and last segment (fn) of the multiple outlet pipe was noted to be minimal.

scholarly journals Investigation of various factors affecting the coefficient of friction of yarn by using Taguchi method

2019 ◽  
Vol 70 (03) ◽  
pp. 211-215
Author(s):  
MOHSIN MUHAMMAD ◽  
NAI-WEN LI ◽  
SOHAIL ANJUM MUHAMMAD ◽  
KASHIF MAJEED MUHAMMAD
Keyword(s):  
Taguchi Method ◽  
Coefficient Of Friction ◽  
Linear Density ◽  
Orthogonal Design ◽  
Taguchi Approach ◽  
Response Factors ◽  
Factors Affecting ◽  
Yarn Quality ◽  
Yarn Twist ◽  
The Coefficient Of Friction

This research aims to analyze certain effects of yarn characteristics such as: cotton type, yarn quality, yarn spinning technique, yarn twist and linear density and yarn finish on coefficient of friction of yarn by using Taguchi approach. For evaluation of levels and response factors, 72 experiments are performed by using L36 orthogonal design twice for Taguchi approach. The results show that yarns comprising of finer fibers, combed, waxed, Rotor spun, optimum twist and low linear density have lowest coefficient of friction of yarn, which ultimately improves subsequent textile processes and improve product qualities.

scholarly journals Physical Simulation for the Flow in Straight and Rectangular Loop Manifolds

2021 ◽  
Vol 27 (3) ◽  
pp. 15-32
Author(s):  
Abdullah A. Rihan ◽  
Thamer A. Mohamed ◽  
Dr. Wissam H. Alawee
Keyword(s):  
Physical Simulation ◽  
Flow Distribution ◽  
Head Loss ◽  
Flow Conditions ◽  
Factors Affecting ◽  
Uniformity Coefficient ◽  
Head Losses ◽  
Supply Tank ◽  
Total Head ◽  
Constant Head

The flow in a manifolds considered as an advanced problem in hydraulic engineering applications. The objectives of this study are to determine; the uniformity qn/q1 (ratio of the discharge at last outlet, qn to the discharge at first outlet, q1) and total head losses of the flow along straight and rectangular loop manifolds with different flow conditions. The straight pipes were with 18 m and 19 m long and with of 25.4 mm (1.0 in) in diameter each. While, the rectangular close loop configuration was with length of 19 m and with diameter of 25.4 mm (1.0 in) also. Constant head in the supply tank was used and the head is 2.10 m. It is found that outlets spacing and manifold configuration are the main factors affecting the uniformity of flow distribution and friction head losses along manifolds. For large value of outlets spacing, the uniformity coefficient (qn/q1) was found with greatest value of 0.96. Thus, the flow distribution improves with bigger spacing between outlets along manifold. For same manifold length, diameter, inlet head and spacing between outlets (S/L=0.079), the uniformity coefficient was found 0.881 or 88.1% for straight manifold and 0.926 for rectangular loop manifold. From the experimental data, a better uniformity is obtained from the rectangular loop manifold, this is because the friction head loss in rectangular loop manifold was lower than that in straight manifold. The lowest of total head losses was found with greatest outlet spacing along manifold, while the highest of total head losses was found with smallest outlets spacing along manifold. And, the lowest of total head loss was found with the rectangular manifold, while the highest of total head loss was found with the straight manifold.

Forces Exerted by Ice on Ships

1968 ◽  
Vol 12 (04) ◽  
pp. 302-312
Author(s):  
H. Estrada ◽  
S. R. Ward
Keyword(s):  
Sea Ice ◽  
Coefficient Of Friction ◽  
Arctic Sea Ice ◽  
Literature Survey ◽  
Factors Affecting ◽  
Arctic Sea ◽  
Hull Design ◽  
The Coefficient Of Friction ◽  
Ice Strength ◽  
Ice Failure

The factors affecting the strength of arctic sea ice are identified. Values are selected for the key parameters that determine ice strength. The selected values are based on a literature survey. The forces resulting from interaction of ice and hull are described in terms of the slope of the hull at the waterline and the coefficient of friction. The mechanism for ice failure is described and the effect of this analysis on hull design is discussed.

Stress in a flat section band clamp

2003 ◽  
Vol 217 (7) ◽  
pp. 821-830 ◽  
Author(s):  
K Shoghi ◽  
H V Rao ◽  
S M Barrans
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Coefficient Of Friction ◽  
Experimental Work ◽  
Rigid Cylinder ◽  
Initial Stage ◽  
The Coefficient Of Friction ◽  
Flat Section ◽  
Band Material

This paper analyses the stress in a flat section band clamp and validates by experimental data the predictions based on the developed theory. In the experimental work flat section band clamps were positioned around the rigid cylinder and strain and corresponding displacement were measured; the clamp nut was tightened to gradually increasing torque until failure occurred. The error in stress and corresponding displacement predicted by the theory and that obtained by testing was found to be 1–2 per cent for the initial stage where the band is slack on the rigid cylinder, 3–5 per cent where the band makes contact with the cylinder and 5–7 per cent for post-yielding of the band material. This error could mainly be attributed to an uncertainty in the properties for the material and the accuracy of instrumentation. The coefficient of friction between the relevant components and the elastic modulus of the band material are the important properties, which influence the performance of the clamp. In the current experimental work failure occurred in the T-bolt.

scholarly journals Analysis of the Anti-Skid Properties of New Airfield Pavements in Aspect of Applicable Requirements

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 778
Author(s):  
Mariusz Zieja ◽  
Mariusz Wesołowski ◽  
Krzysztof Blacha ◽  
Paweł Iwanowski
Keyword(s):  
Coefficient Of Friction ◽  
Field Studies ◽  
Technical Condition ◽  
Measuring System ◽  
Measurement Results ◽  
Cast Doubt ◽  
The Coefficient Of Friction ◽  
Profile Depth ◽  
Actual Field ◽  
New Criterion

The assessment of the anti-skid properties of airfield pavements is one of the elements in the process of determining their current technical condition, which is important in terms of the safety of air operations. The condition of the pavement should be qualified on the basis of the specified and required values (criteria), in this case, the coefficient of friction and the depth of the texture. Unfortunately, in practice, the assessment of the texture of new airfield pavements raises some doubts with regard to the existing requirements. The work presents an analysis of the results of texture tests for new airfield pavements in relation to current requirements. In addition, the authors proposed a new criterion of average texture depth for new airfield pavements, based on actual field measurement results. Field studies used an innovative method of assessing anti-skid properties with a measuring system that allows simultaneous measurement of the coefficient of friction, μ, and the new continuous coefficient of average profile depth and texture CMPTD, from which MPD (Mean Profile Depth) and ETD (Estimated Texture Depth) can be determined. The results of the tests cast doubt on the possibility of obtaining the average texture depth (currently 1.00 mm) required for new airfield pavements.

Factors affecting the coefficient of friction of paper

1992 ◽  
Vol 46 (5) ◽  
pp. 805-814 ◽  
Author(s):  
N. Gurnagul ◽  
M. D. Ouchi ◽  
N. Dunlop-Jones ◽  
D. G. Sparkes ◽  
J. T. Wearing
Keyword(s):  
Coefficient Of Friction ◽  
Factors Affecting ◽  
The Coefficient Of Friction

Modeling of Tribological Characteristics of Specimens with Wear-Resistant Coating Using Dummy Variables

2019 ◽  
Vol 945 ◽  
pp. 919-925 ◽  
Author(s):  
N. Loginov ◽  
O. Khudyakova ◽  
E. Orlova
Keyword(s):  
Coefficient Of Friction ◽  
Quality Parameters ◽  
Manufacturing Processes ◽  
Adequate Model ◽  
Wear Resistant ◽  
Factors Affecting ◽  
Dummy Variables ◽  
Wear Resistant Coatings ◽  
The Coefficient Of Friction ◽  
Qualitative Estimation

In the process of machining, one of the main factors affecting machining tool wear is friction. A decrease in the coefficient of friction between the machining tool and a machined part is a key challenge for researchers. One of the methods to decrease the coefficient of friction and, consequently, to improve the endurance of the tool is the application of wear-resistant coatings. In the current study, modelling of triboprocesses using dummy variables is proposed. Since a peculiarity of modelling of manufacturing processes is a presence of a large number of quality parameters, the influence of all key parameters on the value of the coefficient of friction has been analysed. Also, an adequate model of the dependence of the conditions of the manufacturing process on the coefficient of friction has been developed. The results of the model are important not only for analysis of friction between contact surfaces itself, but also as supplementary and qualitative estimation of different manufacturing processes.

A Deep Drawing Test for Determining the Punch Coefficient of Friction

1981 ◽  
Vol 103 (2) ◽  
pp. 197-202 ◽  
Author(s):  
S. Rajagopal
Keyword(s):  
Experimental Data ◽  
Coefficient Of Friction ◽  
Deep Drawing ◽  
Stress System ◽  
Drawing Test ◽  
The Coefficient Of Friction ◽  
Cylindrical Region ◽  
Deep Drawing Test ◽  
Lubrication Conditions

A deep drawing test is described for measuring the coefficient of friction between the cylindrical surfaces of the punch and the cup wall. The test is based on an analysis of the stress system in the cylindrical region of contact. Experimental data are presented for steel and aluminum blanks deep-drawn into cups under different lubrication conditions, and the advantages and limitations of the method are discussed.

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