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Number of results: 9
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Abstract

Water is the main source of daily life for everyone and everywhere in the world. Sufficient water distribution depends on the place and design of water tank in certain areas. Water storage tanks are relatively flexible structures and they can tolerate greater settlements than other engineering structures. Deformation of tanks may cause severe damages to tank or even loss of life and injury to people, so monitoring the structural deformation and dynamic response of water tank and its supporting system to the large variety of external loadings has a great importance for maintaining tank safety and economical design of manmade structures. This paper presents an accurate geodetic observations technique to investigate the inclination of an elevated circular water tank and the deformation of its supporting structural system (supporting columns and circular horizontal beams) using reflector-less total station. The studied water tank was designed to deliver water to around 55000 person and has a storage capacity about 750 m3. Due to the studied water tank age, a non-uniform settlement of tank foundation and movement of pumps and electric machines under tank’s body will cause stress and strain for tanks membrane and settlement of sediments. So the studied water tank can tend to experience movement vertically, horizontally or both. Three epochs of observations were done (July 2014, September 2014 and December 2014). The results of the practical measurements, calculations and analysis of the interesting deformation of the studied elevated tanks and its supporting system using least squares theory and computer programs are presented. As a results of monitoring the water storage tank, circular reinforced concrete beams and columns at three monitoring epochs. The body of water storage tank has an inclination to the east direction and the value of inclination is increased with the time.

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Authors and Affiliations

Zaki Zeidan
Ashraf A.A. Beshr
Sara Sameh
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Abstract

The paper depicts the relations between historian person and history cognition, especially the influence of his mind inclinations to cognitive biases on narrative.
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Authors and Affiliations

Maciej Dymkowski
ORCID: ORCID
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Abstract

The article presents the problem of structural friction appearing in a screw joint with frictional effects between its elements. In the article, two mathematical models of screw joint are analysed. In the first model, high stiffness of a nut is assumed. In the second model, the influence of both cooperating elements (the screw and nut) is assumed.

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Authors and Affiliations

Wojciech Kaczmarek
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Abstract

The draw theory is the foundation for decreasing ore loss and dilution indices while extracting deposits from mines. Therefore, research on draw theory is of great significance to optimally guide the draw control and improve the economy efficiency of mines. The laboratory scaled physical draw experiments under inclined wall condition conducted showed that a new way was proposed to investigate the flow zone of granular materials. The flow zone was simply divided into two parts with respect to the demarcation point of the flow axis. Based on the stochastic medium draw theory, theoretical movement formulas were derived to define the gravity flow of fragmented rocks in these two parts. The ore body with 55° dip and 10 m width was taken as an example, the particle flow parameters were fitted, and the corresponding theoretical shape of the draw body was sketched based on the derived equation of draw-body shape. The comparison of experimental and theoretical shapes of the draw body confirmed that they coincided with each other; hence, the reliability of the derived equation of particle motion was validated.

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Authors and Affiliations

Xiufeng Zhang
Ganqiang Tao
Zhonghua Zhu
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Abstract

The performance of ten wickless heat pipes without adiabatic sections is investigated experimentally at low heat inputs 120 to 2000 W/m2 for use in solar water heaters. Three heat pipe diameter groups were tested, namely 16, 22, and 28.5 mm. Each group had evaporator lengths of 1150, 1300, and 1550 mm, respectively, with an extra evaporator length of 1800 mm added to the second group. The condenser section length of all heat pipes was 200 mm. Ethanol, methanol, and acetone were utilized as working fluids, at inventory of 25%, 50%, 70%, and 90% by evaporator volume respectively. The 22 mm diameter pipes were tested at inclination angles 30◦, 45◦, and 60◦. Other diameter groups were tested at 45◦ only. Experiments revealed increased surface temperatures and heat transfer coefficients with increased pipe diameter and evaporator length, and that increased working fluid inventory caused pronounced reduction in evaporator surface temperature accompanied by improved heat transfer coefficient to reach maximum values at 50% inventory for the selected fluids. Violent noisy shocks were observed with 70% and 90% inventories with the tested heat pipes and the selected working fluids with heat flux inputs from 320–1900 W/m2. These shocks significantly affected the heat pipes heat transfer capability and operation stability. Experiments revealed a 45◦ and 50% optimum inclination angle of fill charge ratio respectively, and that wickless heat pipes can be satisfactorily used in solar applications. The effect of evaporator length and heat pipe diameter on the performance was included in data correlations.

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Authors and Affiliations

Hassan Naji Salman Al-Joboory
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Abstract

Heat transfer study from the heated square cylinder at a different orientation angle to the stream of nanofluids has been investigated numerically. CuO-based nanofluids were used to elucidate the significant effect of parameters: Reynolds number (1–40), nanoparticle volume fraction (0.00–0.05), the diameter of the NPs (30–100 mn) and the orientation of square cylinder (0–90°). The numerical results were expressed in terms of isotherm contours and average Nusselt number to explain the effect of relevant parameters. Over the range of conditions, the separation of the boundary layers of nanofluids increased with the size of the NPs as compared to pure water. NPs volume fraction and its size had a significant effect on heat transfer rate. The square cylinder of orientation angle (45°) gained a more efficient heat transfer cylinder than other orientation angles. Finally, the correlations were developed for the average Nusselt number in terms of the relevant parameters for 45° orientation of the cylinder for new applications.
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Authors and Affiliations

Jaspinder Kaur
1
Jatinder Kumar Ratan
1
Anurag Kumar Tiwari
1

  1. Dr B.R. Ambedkar National Institute of Technology Jalandar Punjab, Chemical Engineering Department, Pin code 144011, India
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Abstract

An axial flow tubular heat exchanger has been experimentally investigated to augment the heat transfer rate with a novel swirl flow of air past the heated tubes. The novel design has been based on circular baffle plates provided with trapezoidal air deflectors of various inclination angles. The arrangement of tubes is kept the same throughout the experiment, in accordance with the longitudinal airflow direction. The tubes maintained a constant heat flux condition over the surface. Four deflectors with equal inclination angles were developed on each baffle plate, generating air swirl inside a circular duct carrying the heated tubes that increase air-side turbulence and, consequently, the surface heat transfer rate. The baffle plates were placed equidistant from each other at variable pitch ratios. The Reynolds number was kept in the range of 16000– 28000. The effect of pitch ratios and inclination angles on the thermo-fluid performance of the heat exchanger was studied. The investigations revealed an average improvement of 3.75 times in thermo-fluid performance for an exchanger with a deflector baffle plate with a baffle inclination angle of 50_ and a pitch ratio of 1.4 when compared to other inclination angles and pitch ratios.
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Authors and Affiliations

Md Atiqur Rahman
1
ORCID: ORCID
Sushil Kumar Dhiman
1

  1. Department of Mechanical Engineering, Birla Institute of Technology, Mesra, Ranchi, India
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Abstract

The speed of test vehicles on the high-speed car track of the automobile test field is very high. Reducing the construction error of asphalt pavement is very important to ensure the safety of the test vehicle. In order to realize the paving of asphalt concrete pavement with super-large lateral inclination in the curve section of the high-speed car track in the automobile test field, a special paving control device and control method for the construction on the curve section with super-large lateral inclination were developed. Use the direction of the hanging hammer under the GPS device of paver to adjust the position of GPS device in real time, so that the geometric centre line of GPS device is always perpendicular to the horizontal plane. The reference control line is preset in the paver operation control device, and the lateral displacement deviation of the paver is adjusted to synchronize the data of the paver control device with the travel route. The precise control of the paver’s forward route is realized, the construction precision of the super-large inclined asphalt pavement on the high-speed car track of the automobile test field is achieved, and the construction efficiency is greatly improved. It has important reference value for similar projects such as automobile testing field and racing track.
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Authors and Affiliations

Yongzheng Qi
1 2
ORCID: ORCID
Wengang Ma
3
ORCID: ORCID
Jiesheng Zhang
4
ORCID: ORCID

  1. Key Laboratory of Flood & Drought Disaster Defense, the Ministry of Water Resources, Nanjing 210029, China
  2. Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, No. 2 Mengxi Road, Zhenjiang 212003, China
  3. Institute of Civil Engineering and Intelligent Management, Nanjing Institute of Technology, Nanjing 211167, China
  4. The First Engineering Co., LTD. of CTCE Group, No. 434 Fuyang North Road, Hefei 230041, China
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Abstract

Inclinedweb box girders are widely used in urban areas because of their attractive appearance. However, there are few studies on the vehicle shear force distribution of this type of bridge. In this study, we established 62 three-dimensional finite element models in which the shear force of each web of the box girder can be extracted; furthermore, we investigated the shear force distribution law in webs of the box girder under live loads, including single-chamber and multichamber inclined web box girders. The main parameters studied include the number of vehicle lanes and chambers, slope of the inclined webs, and support conditions. The results reveal that an uneven distribution of web shear force exists in both the single-chamber box girder and multichamber girder under live loads, and the maximum value of the vehicle shear force distribution factor is greater than the average shear value shared by all webs. Therefore, the uneven distribution of shear force in the webs of the box girder cannot be ignored under eccentric vehicle loads. These values greatly exceed the safety factor of 1.15 that is used in conventional calculations.
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Authors and Affiliations

Yujun Cui
1
ORCID: ORCID
Longqing Wu
1
ORCID: ORCID
Weiqi Wang
1
ORCID: ORCID
Wei Cao
1
ORCID: ORCID
Xingwei Xue
1
ORCID: ORCID

  1. School of Traffic Engineering, Shenyang Jianzhu University, Shenyang, Liaoning, China

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