scholarly journals The EFFECT OF HYDROPHYTES ON THE PERFORMANCE OF SECONDARY CANAL

2021 ◽  
Vol 27 (4) ◽  
pp. 565-576
Author(s):  
Haroon Khan
Keyword(s):  
Cross Section ◽  
Irrigation System ◽  
Canal Irrigation ◽  
Cross Section Area ◽  
Section Area ◽  
Secondary Canal ◽  
Triangular Profile ◽  
Current Water ◽  
Raise Water Level ◽  
The University

The hydrophytes in canal effect directly canal performance by reducing water velocity, enhances sedimentation and reduce canal cross section area which raise water level and reduces water flow. Indirectly the hydrophytes detaches from their origin and flow with water stuck with outlet and reduces its proportionality. In this regard a study was conducted on secondary canal known as Yar Husain Minor (YHM) of Maira Branch Canal, which is part of the Upper Swat Canal Irrigation System in Khyber Pakhtunkhwa, Pakistan. Maira Branch Canal and its secondary canal were designed for Crop Based Irrigation Operation (CBIO), which could supply irrigation water for maximum copping intensity (180%) even during peak periods of irrigation requirements. The current water allowance was 0.67 Ls-1 ha-1 (6.6 mm day-1), which was based on the maximum crop water requirements. The several challenges for operation of YHM and other secondary canals of Maira Branch came from physical barrier mostly in the form of hydrophytes on the performance of YHM canal. Further challenges came from the fact that it receives water from River Swat which is turbid in summer and River Indus (Tarbela Reservoir) which is clear with low turbidity. This caused sedimentation and growth of hydrophytes in the YHM. Furthermore Triangular Profile Crump’s weirs were in all secondary canals including YHM for proportional division to the tertiary outlets (moghas). The study objectives were to investigate the effects of hydrophytes on canal capacity and at the outlets on the performance of the YHM. Hydrophytes growth was observed in head reaches of canal and samples were collected and were identified at the Department of Weed Science & Botany, The University of Agriculture Peshawar. Five types of aquatic weeds were identified. The hydrophytes growth in canal head reaches directly reduces the cross section by more than 50%. Indirectly the detached hydrophytes were get stuck in the outlets and affected its performance. Therefore, daily discharges were measured with/without detached hydrophytes at each outlet from staff gauging. Frequency was based on days stone hydrophytes present divided by total time. It was concluded that secondary canal performance was low due to hydrophytes. The hydrophytes and users interventions influenced the outlets performance by 80%. Trifurcators type outlets were more prone to influence by hydrophytes followed by bifurcators outlet.  

Thermoacoustic Shape Optimization of a Subsonic Nozzle

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Alexis Giauque ◽  
Maxime Huet ◽  
Franck Clero ◽  
Sébastien Ducruix ◽  
Franck Richecoeur
Keyword(s):  
Acoustic Emission ◽  
Cross Section ◽  
Source Term ◽  
Combustion Noise ◽  
Noise Emission ◽  
Cross Section Area ◽  
Section Area ◽  
The Cross ◽  
Nozzle Flows ◽  
Subsonic Nozzle

Indirect combustion noise originates from the acceleration of nonuniform temperature or high vorticity regions when convected through a nozzle or a turbine. In a recent contribution (Giauque et al., 2012, “Analytical Analysis of Indirect Combustion Noise in Subcritical Nozzles,” ASME J. Eng. Gas Turbies Power, 134(11), p. 111202) the authors have presented an analytical thermoacoustic model providing the indirect combustion noise generated by a subcritical nozzle when forced with entropy waves. This model explicitly takes into account the effect of the local changes in the cross-section area along the configuration of interest. In this article, the authors introduce this model into an optimization procedure in order to minimize or maximize the thermoacoustic noise emitted by arbitrarily shaped nozzles operating under subsonic conditions. Each component of the complete algorithm is described in detail. The evolution of the cross-section changes are introduced using Bezier's splines, which provide the necessary freedom to actually achieve arbitrary shapes. Bezier's polar coordinates constitute the parameters defining the geometry of a given individual nozzle. Starting from a population of nozzles of random shapes, it is shown that a specifically designed genetic optimization algorithm coupled with the analytical model converges at will toward a quieter or noisier population. As already described by Bloy (Bloy, 1979, “The Pressure Waves Produced by the Convection of Temperature Disturbances in High Subsonic Nozzle Flows,” J. Fluid Mech., 94(3), pp. 465–475), the results therefore confirm the significant dependence of the indirect combustion noise with respect to the shape of the nozzle, even when the operating regime is kept constant. It appears that the quietest nozzle profile evolves almost linearly along its converging and diverging sections, leading to a square evolution of the cross-section area. Providing insight into the underlying physical reason leading to the difference in the noise emission between two extreme individuals, the integral value of the source term of the equation describing the behavior of the acoustic pressure of the nozzle is considered. It is shown that its evolution with the frequency can be related to the global acoustic emission. Strong evidence suggest that the noise emission increases as the source term in the converging and diverging parts less compensate each other. The main result of this article is the definition and proposition of an acoustic emission factor, which can be used as a surrogate to the complex determination of the exact acoustic levels in the nozzle for the thermoacoustic shape optimization of nozzle flows. This acoustic emission factor, which is much faster to compute, only involves the knowledge of the evolution of the cross-section area and the inlet thermodynamic and velocity characteristics to be computed.

An Analytical Method of Analyzing the Heat Conduction for the Unequal Cross-Section Straight Fin

2013 ◽  
Vol 365-366 ◽  
pp. 1211-1216
Author(s):  
Fan Zhang ◽  
Peng Yun Song
Keyword(s):  
Heat Conduction ◽  
Cross Section ◽  
Analytical Method ◽  
Thermal Analyses ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Calculation Results ◽  
The Cross ◽  
Analytical Expressions

The cross-section area of straight fin is often considered to be equal in the thermal analyses of straight fin, but sometimes it is unequalin actual situation. Taking a straight fin with two unequal cross-sectional areas as an example,an analytical method of heat conduction for unequal section straight fin is presented. The analytical expressions of temperature field and heat dissipating capacity about the fin,which has a smaller cross-section area near the fin base and a larger one, is obtained respectively. The calculation results of the unequal cross-section are fully consistent with the equal area one, so the method is proved right. The results show that the larger the cross section areanear the base,the better is the heat transfer, and the temperature at the base with larger cross-section area is lower than that with smaller cross-section area when the amount of heat is fixed.

Rotational Temperature Measurement in Multicomponent Gases Using Raman Scattering Spectroscopy

1976 ◽  
Vol 30 (2) ◽  
pp. 179-183 ◽  
Author(s):  
R. S. Hickman ◽  
A. E. Kassem ◽  
L. H. Liang
Keyword(s):  
Temperature Field ◽  
Raman Scattering ◽  
Temperature Measurement ◽  
Cross Section ◽  
Room Temperature ◽  
Rotational Temperature ◽  
Raman Scattering Spectroscopy ◽  
Scattering Experiment ◽  
Cross Section Area ◽  
Section Area

The rotational temperature at pressures near 1 atm and at room temperature has been successfully measured using spectra obtained in an intracavity Raman scattering experiment. The accuracy of the method is sufficient to allow local temperature measurement of multicomponent gases with no disturbance in the temperature field. The advantage of the method lies in the fact that it does not require knowledge of the relative scattering cross-section area of the component gases.

scholarly journals Load bearing capacity of thin-walled rectangular and I-shaped steel sections of short both empty and concrete-filled columns

2021 ◽  
Vol 15 (58) ◽  
pp. 77-85
Author(s):  
Amor Bouaricha ◽  
Naoual Handel ◽  
Aziza Boutouta ◽  
Sarah Djouimaa
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Load Capacity ◽  
Cross Sectional ◽  
Short Columns ◽  
Cross Section Area ◽  
Section Area ◽  
Specimen Height ◽  
Steel Sections ◽  
Thin Walled

In this experimental work, strength results obtained on short columns subjected to concentric loads are presented. The specimens used in the tests have made of cold-rolled, thin-walled steel. Twenty short columns of the same cross-section area and wall thickness have been tested as follows: 8 empty and 12 filled with ordinary concrete. In the aim to determine the column section geometry with the highest resistance, three different types of cross-sections have been compared: rectangular, I-shaped unreinforced and, reinforced with 100 mm spaced transversal links. The parameters studied are the specimen height and the cross-sectional steel geometry. The registered experimental results have been compared to the ultimate loads intended by Eurocode 3 for empty columns and by Eurocode 4 for compound columns. These results showed that a concrete-filled composite column had improved strength compared to the empty case. Among the three cross-section types, it has been found that I-section reinforced is the most resistant than the other two sections. Moreover, the load capacity and mode of failure have been influenced by the height of the column. Also, it had noted that the experimental strengths of the tested columns don’t agree well with the EC3 and EC4 results.

Mathematical Model Analysis of Dispersion and Loss in Photonic Crystal Fibers

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
IS Amiri ◽  
P. Yupapin ◽  
Ahmed Nabih Zaki Rashed
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Cross Section ◽  
Photonic Crystal Fibers ◽  
Effective Cross Section ◽  
Confinement Loss ◽  
Cross Section Area ◽  
Section Area ◽  
Crystal Fibers ◽  
Analysis Of Dispersion

AbstractThis study has deeply investigated the basic equations analysis of dispersion and loss in photonic crystal fibers (PCF) within the operating wavelengths of 850, 1,300, and 1,550 nm. The confinement loss, effective refractive index, and effective cross-section area of PCF are also studied. The variations of total dispersion and losses against hole diameter and distance between holes variations in PCF are clarified. Confinement loss, effective refractive index, and effective cross-section area variations for PCF are sketches with the variations of the operating wavelength.

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