scholarly journals Theoretical solution for analysis and design of hydraulic jump on corrugated bed

Water SA ◽  
2018 ◽  
Vol 44 (4 October) ◽  
Author(s):  
Jahanshir Mohammadzadeh-Habili ◽  
Tooraj Honar
Keyword(s):  
Energy Dissipation ◽  
Hydraulic Jump ◽  
Energy Curve ◽  
Horizontal Distance ◽  
Sluice Gate ◽  
Analysis And Design ◽  
Minimum Value ◽  
Maximum Value ◽  
Wide Range ◽  
Sequent Depth

A hydraulic jump mainly serves as an energy dissipator downstream of hydraulic structures. For analysis and design of a hydraulic jump on a corrugated bed, the specific energy curve was used: the maximum possible amount of energy dissipation of the hydraulic jump, the minimum possible value of sequent depth for the hydraulic jump, and efficiency of energy dissipation of a smooth hydraulic jump are theoretically related to the inflow Froude number. A wide range of existing experimental data from hydraulic jumps on smooth and corrugated beds was also used. Results of this study indicate that the energy dissipation of a hydraulic jump on a corrugated bed is mainly influenced by horizontal distance from the sluice gate section to the start point of the corrugated bed. To reach the maximum value of energy dissipation (i.e., minimum value of subcritical sequent depth) and the minimum value of jump length, the corrugated bed should start from the gate opening.

The Baffle Blocks Effects of Pressure Characteristics on USBR III Basin Floor

2012 ◽  
Vol 212-213 ◽  
pp. 821-825
Author(s):  
Keyvan Nasiri ◽  
Mohammad Reza Kavianpour ◽  
Siavash Haghighi
Keyword(s):  
Energy Dissipation ◽  
Hydraulic Jump ◽  
Pressure Fluctuations ◽  
Power Spectra ◽  
Low Frequency ◽  
Dominant Frequency ◽  
Energy Dissipation Rate ◽  
Tension And Compression ◽  
Basin Floor ◽  
Sequent Depth

The principle of energy dissipation in stilling basin is based on hydraulic jump formation. Due to the inherent fluctuating characteristic of the hydraulic jump, basin floor is subjected to variations of pressure, resulting in unstableness due to uplift forces. To increase the efficiency of the stilling basins and improve the energy dissipation rate, one or two rows of baffle blocks are applied on the basin floor. Causing a forced hydraulic jump, tension and compression forces are exerted by pressure fluctuations of rotating roller zone of hydraulic jump. In this investigation, to observe the impacts of baffle blocks on pressure fluctuations on basin floor, a standard USBR basin model type III was constructed, and then a second row of blocks was added to the basin. A set of pressure tubes was fixed along the axis of the basin to measure the static and dynamic pressures on basin floor. The results were expressed in dimensionless parameters including C-p, C+p, C’p, Cp. Also, power spectra of pressure fluctuations were calculated. The results show a decreasing trend in root mean square of pressure fluctuations as distancing from toe of jump along the basin with and without baffle blocks. Also, mean pressure increases when water jet strokes the basin then decreases under roller zone of jump and increases again after sequent depth. The spectral analysis indicates that the dominant frequency is between 10 rad/s and 35 rad/s and pressure fluctuations have low frequency characteristics.

Experimental Study of Sand Sediments Effects on Submerged Hydraulic Jump Properties

2012 ◽  
Vol 212-213 ◽  
pp. 366-371
Author(s):  
Siavash Haghighi ◽  
Mohammad Reza Kavianpour ◽  
Keyvan Nasiri
Keyword(s):  
Energy Dissipation ◽  
Hydraulic Jump ◽  
Suspended Sediment Concentration ◽  
Sediment Load ◽  
Sediment Concentration ◽  
Relative Energy ◽  
Sluice Gate ◽  
Jump Length ◽  
Submerged Hydraulic Jump ◽  
Whole Sediments

Abstract. In this study, the effect of sediment concentration on submerged hydraulic jump (SHJ) characteristics such as jump length, submerged depth on the gate and the energy dissipation is investigated. Experiments were carried out in a flume of 46 cm depth, 12 m length. The width of the flume changes from 10 cm (at the entrance) to 60 cm (at the exit). Sediment load and flow concentration have an influence on submerged hydraulic jump characteristics including submerged depth on the gate, jump length and relative energy dissipation. It is shown that at high Froude numbers increasing the suspended sediment concentration to 28.7 gr/l leads to a reduction in the submerged depth on the gate up to 6% and jump length up to 10%. Also, the energy dissipation of the submerged hydraulic jump increases by 4% and turbulence resulting from the jump leads to upright distribution of concentration at the end of the jump. Also in concentrations higher than 30 gr/l, flow is not able to carry the whole sediments and subsequently leads to their deposition in subcritical area and behind the sluice gate.

scholarly journals Effect of roughness on sequent depth in hydraulic jumps over rough bed

2019 ◽  
Vol 71 (2) ◽  
pp. 105-111
Author(s):  
Arpan Arunrao Deshmukh ◽  
Naveen Sudharsan ◽  
Avinash D Vasudeo ◽  
Aniruddha Dattatraya Ghare
Keyword(s):  
Energy Dissipation ◽  
Kinetic Energy ◽  
Hydraulic Jump ◽  
Open Channel ◽  
Hydraulic Jumps ◽  
Open Channel Flows ◽  
Downstream Side ◽  
Rough Bed ◽  
Sequent Depth ◽  
Rough Beds

Hydraulic jump is an important phenomenon in open channel flows such as rivers and spillways. Hydraulic jump is mainly used for kinetic energy dissipation at the downstream side of a spillway with the assist of baffle blocks. It has been demonstrated that corrugated or rough beds show considerably more energy dissipation than smooth beds. The experimental research evaluating the effect of crushed stones on the hydraulic jump is presented in this paper. Five different-size sets of crushed stones were used. Results show that the effect of rough bed does not increase after a certain height of crushed stone is reached.

scholarly journals Effect of baffle block configurations on characteristics of hydraulic jump in adverse stilling basins

2018 ◽  
Vol 162 ◽  
pp. 03005
Author(s):  
Ali Abbas ◽  
Haider Alwash ◽  
Ali Mahmood
Keyword(s):  
Energy Dissipation ◽  
Hydraulic Jump ◽  
Block Model ◽  
Double Row ◽  
Stilling Basin ◽  
Depth Ratio ◽  
Stilling Basins ◽  
Sequent Depth ◽  
Baffle Block ◽  
Energy Dissipation Ratio

The construction of stilling basin with adverse slope change the characteristics of hydraulic jump such as sequent depth ratio, length of jump ratio, length of roller and energy dissipation ratio, consequently the dimensions of stilling basin are changed, also using baffle blocks with different configurations develop these characteristics. In this study different shapes of baffle block (models (A), (B), (C) and (D)) installed in the stilling basins at adverse slopes (- 0.03, - 0.045, - 0.06) in addition to horizontal bed, all these models are tested in the stilling basin to show their effects on the characteristics of hydraulic jump, the experiments applied for the range of Froude number (Fr1) between 3.99 and 7.48. The baffle block model (D) showed good results when compared with models (B) and (C), therefore it used with arrangement of (single and double row) and compared with baffle block model (A) at slopes (0, - 0.03, - 0.045, - 0.06) to study the effects of baffle blocks on hydraulic jump when bed slopes are changed. In general using baffle block caused a reduction in sequent depth ratio, length of jump ratio and the length of the roller, but the energy dissipation ratio increased.

scholarly journals The Effect of Infill Steel Plate Thickness on the Cycle Behavior of Steel Plate Shear Walls

2018 ◽  
Vol 11 (3) ◽  
pp. 7-13 ◽  
Author(s):  
Ali Sadik Abbas
Keyword(s):  
Energy Dissipation ◽  
Hydraulic Jump ◽  
Steel Plate ◽  
Plate Thickness ◽  
Shear Walls ◽  
Depth Ratio ◽  
Stilling Basins ◽  
Bed Slope ◽  
Sequent Depth ◽  
Energy Dissipation Ratio

The effect of changing in the bed slope of stilling basins produces changing in characteristics of the hydraulic jump such as sequent depth ratio, length of jump ratio, length of the roller and energy dissipation ratio, consequently the dimensions of stilling basin changed. In this study hydraulic jump investigated on smooth bed (without any appurtenances) for three adverse slopes (- 0.03, - 0.045, - 0.06) in addition to horizontal bed slope, the experiments were applied for the range of Froude number (Fr1) between 3.99 and 7.48. The results showed a reduction about10 % in sequent depth ratio, 22.1 % in length of jump ratio, 20.51 % in length of roller ratio and 13.87% in the energy dissipation ratio when the adverse slope (- 0.06) used instead of horizontal bed for the same Froude numbers. Empirical equations for the sequent depth ratio, length of roller ratio and the energy dissipation ratio were obtained from the experimental data

scholarly journals Hydraulic Jump and Energy Dissipation with Sluice Gate

Water ◽  
2015 ◽  
Vol 7 (9) ◽  
pp. 5115-5133 ◽  
Author(s):  
Youngkyu Kim ◽  
Gyewoon Choi ◽  
Hyoseon Park ◽  
Seongjoon Byeon
Keyword(s):  
Energy Dissipation ◽  
Hydraulic Jump ◽  
Sluice Gate

Physico-Chemical Characteristics of Sapota (Chikoo) Powder based Value Added Pasta Product using Semolina (Suji) and Maida

2020 ◽  
Vol 7 (04) ◽  
Author(s):  
SATYA NARAYAN SINGH ◽  
RAJESH G BURBADE ◽  
HITESH SANCHAVAT ◽  
P S PANDIT
Keyword(s):  
Bulk Density ◽  
Crude Protein ◽  
Water Solubility ◽  
Value Added ◽  
Absorption Capacity ◽  
Oil Absorption ◽  
Minimum Value ◽  
Maximum Value ◽  
Physico Chemical ◽  
Specific Length

The cereals of today are more nutritious and healthful than ever before. Cereals processing is one of the oldest and the most essential part of all food technologies. Pasta products and noodles have been staple foods since ancient times in many countries all over the world. In this study pasta formulation was substituted with blending sapota powder in different proportions (4 levels i.e. 0%, 10%, 20%, 30%) into semolina and maida flour separately. Pasta products were prepared using eight different formulations and adding water (approximately 31% of total weight) in DOLLY pasta extruder machine. All the samples were evaluated for physical properties: specific length (mm/g), bulk density (kg/m3), specific density (kg/m3) and porosity (%); functional properties: water absorption index (%), water solubility index (%) and oil absorption capacity (ml/g) and nutritional compositions: moisture (%), crude protein (%), fat (%) and carbohydrate (%). Highest specific length 36.20 mm/g was observed for T5 treatment, low bulk density 368.10 kg/m3 was observed for T5 and highest porosity 9.24% was found for T1 treatment. The maximum WAI, WSI values 325.83%, 17.33% respectively was observed for T1 treatment and minimum value of oil absorption capacity 1.06 ml/g for T8 treatment. The moisture content of dried pasta products was found in the range of 6 to 7%. The maximum value of crude protein 13.07% was found for T5 and minimum value 8.81% for T4 treatments. The fat contents were varied from 1.02% to 1.28 %. The maximum value of carbohydrate was 76.20% for T1 and minimum value 65.41% for T8.

Reactive Ion Etching Induced Surface Damage of Silicon Carbide

2005 ◽  
Vol 483-485 ◽  
pp. 765-768 ◽  
Author(s):  
Jun Hai Xia ◽  
E. Rusli ◽  
R. Gopalakrishnan ◽  
S.F. Choy ◽  
Chin Che Tin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Reactive Ion Etching ◽  
Surface Damage ◽  
Textured Surface ◽  
Rf Power ◽  
Power Devices ◽  
Ion Etching ◽  
Maximum Value ◽  
Wide Range ◽  
Coarse Surface

Reactive ion etching of SiC induced surface damage, e.g., micromasking effect induced coarse and textured surface, is one of the main concerns in the fabrication of SiC based power devices [1]. Based on CHF3 + O2 plasma, 4H-SiC was etched under a wide range of RF power. Extreme coarse and textured etched surfaces were observed under certain etching conditions. A super-linear relationship was found between the surface roughness and RF power when the latter was varied from 40 to 160 W. A further increase in the RF power to 200 W caused the surface roughness to drop abruptly from its maximum value of 182.4 nm to its minimum value of 1.3 nm. Auger electron spectroscopy (AES) results revealed that besides the Al micromasking effect, the carbon residue that formed a carbon-rich layer, could also play a significant role in affecting the surface roughness. Based on the AES results, an alternative explanation on the origin of the coarse surface is proposed.

Observations of Small-Scale Turbulence and Energy Dissipation Rates in the Cloudy Boundary Layer

2006 ◽  
Vol 63 (5) ◽  
pp. 1451-1466 ◽  
Author(s):  
Holger Siebert ◽  
Katrin Lehmann ◽  
Manfred Wendisch
Keyword(s):  
Boundary Layer ◽  
Energy Dissipation ◽  
Wind Velocity ◽  
Turbulence Theory ◽  
Horizontal Wind ◽  
Inertial Subrange ◽  
Intermittent Flow ◽  
Small Scale ◽  
Dissipation Rates ◽  
Wide Range

Abstract Tethered balloon–borne measurements with a resolution in the order of 10 cm in a cloudy boundary layer are presented. Two examples sampled under different conditions concerning the clouds' stage of life are discussed. The hypothesis tested here is that basic ideas of classical turbulence theory in boundary layer clouds are valid even to the decimeter scale. Power spectral densities S( f ) of air temperature, liquid water content, and wind velocity components show an inertial subrange behavior down to ≈20 cm. The mean energy dissipation rates are ∼10−3 m2 s−3 for both datasets. Estimated Taylor Reynolds numbers (Reλ) are ∼104, which indicates the turbulence is fully developed. The ratios between longitudinal and transversal S( f ) converge to a value close to 4/3, which is predicted by classical turbulence theory for local isotropic conditions. Probability density functions (PDFs) of wind velocity increments Δu are derived. The PDFs show significant deviations from a Gaussian distribution with longer tails typical for an intermittent flow. Local energy dissipation rates ɛτ are derived from subsequences with a duration of τ = 1 s. With a mean horizontal wind velocity of 8 m s−1, τ corresponds to a spatial scale of 8 m. The PDFs of ɛτ can be well approximated with a lognormal distribution that agrees with classical theory. Maximum values of ɛτ ≈ 10−1 m2 s−3 are found in the analyzed clouds. The consequences of this wide range of ɛτ values for particle–turbulence interaction are discussed.

Sign in / Sign up

Export Citation Format

Share Document