Swiping/pulse portable nozzle rainfall simulator

2020 ◽  
Author(s):  
Martin Neumann ◽  
Petr Kavka ◽  
Tomáš Laburda ◽  
Adam Tejkl
Keyword(s):  
Kinetic Energy ◽  
Water Flow ◽  
Rainfall Intensity ◽  
Control Unit ◽  
Stepper Motor ◽  
Vertical Position ◽  
Rainfall Simulator ◽  
Flow Interruption ◽  
Wide Range ◽  
Electric Water Pump

<p>Research of surface runoff, retention and infiltration processes consequenced with soil erosion by water is worldwide problem. There are numerous of natural and artificial research methods to study this phenomena. Use of rainfall simulators is one of the most popular artificial method. There are many types of rainfall simulators, we are introducing new type of portable nozzle-type rainfall simulator. This device combines advantages of pulse and swiping nozzle droplet generation. Device criteria were: (i) 2 person operation (ii) low water consumption (iii) wide range of rainfall intensity and kinetic energy. The simulator is supported by 4 metal legs. One fast-replaceable nozzle is placed above the center of a plot in 2 or 2,5 m height. Nozzle is connected to a control unit with stepper motor which allows it to swing, or stay in the vertical position with water flow interruption (solenoid valve). Required rainfall intensity is controlled by the velocity of stepper motor and water flow interruption periods. Metal collector is placed under the nozzle to drain the surplus water back to the reservoir. Standalone electric water pump is used to pump water into the system. 12 V DC and 230 V AC electricity supply is needed to run the device. Experimental plot can be up to 4 m<sup>2</sup> (2x2 m square) in size but usually a 1 m<sup>2</sup> (1x1 m) is used. Rainfall intensity could be used up to 100 mm h<sup>-1</sup>. Kinetic energy for the tested nozzles were 4 – 5,5 J m<sup>-2</sup> mm<sup>-1</sup>. The first testing shows Christiansen Uniformity up to 93% for 1 m<sup>2</sup> plot and 73% for 4 m<sup>2</sup> plot. The research has been carried out within the framework of projects QK1910029, TJ02000234 and TH02030428.[M3] </p>

scholarly journals Measurement and computation of kinetic energy of simulated rainfall in comparison with natural rainfall

2018 ◽  
Vol 13 (No. 4) ◽  
pp. 226-233 ◽  
Author(s):  
Petrů Jan ◽  
Kalibová Jana
Keyword(s):  
Kinetic Energy ◽  
Drop Size ◽  
Rainfall Intensity ◽  
Soil Aggregates ◽  
Meteorological Parameter ◽  
Simulated Rainfall ◽  
Fall Velocity ◽  
Rainfall Simulator ◽  
Rainfall Characteristics ◽  
Natural Rainfall

Rainfall characteristics such as total amount and rainfall intensity (I) are important inputs in calculating the kinetic energy (KE) of rainfall. Although KE is a crucial indicator of the raindrop potential to disrupt soil aggregates, it is not a routinely measured meteorological parameter. Therefore, KE is derived from easily accessible variables, such as I, in empirical laws. The present study examines whether the equations which had been derived to calculate KE of natural rainfall are suitable for the calculation of KE of simulated rainfall. During the experiment presented in this paper, the measurement of rainfall characteristics was carried out under laboratory conditions using a rainfall simulator. In total, 90 measurements were performed and evaluated to describe the rainfall intensity, drop size distribution and velocity of rain drops using the Thies laser disdrometer. The duration of each measurement of rainfall event was 5 minutes. Drop size and fall velocity were used to calculate KE and to derive a new equation of time-specific kinetic energy (KE<sub>time</sub> – I). When comparing the newly derived equation for KE of simulated rainfall with the six most commonly used equations for KE<sub>time</sub> – I of natural rainfall, KE of simulated rainfall was discovered to be underestimated. The higher the rainfall intensity, the higher the rate of underestimation. KE of natural rainfall derived from theoretical equations exceeded KE of simulated rainfall by 53–83% for I = 30 mm/h and by 119–275% for I = 60 mm/h. The underestimation of KE of simulated rainfall is probably caused by smaller drops formed by the rainfall simulator at higher intensities (94% of all drops were smaller than 1 mm), which is not typical of natural rainfall.

scholarly journals Set-up and calibration of a portable small scale rainfall simulator for assessing soil erosion processes at interrill scale

2017 ◽  
Vol 43 (1) ◽  
pp. 63 ◽  
Author(s):  
J. J. Zemke
Keyword(s):  
Soil Erosion ◽  
Kinetic Energy ◽  
Rainfall Intensity ◽  
Small Scale ◽  
Rainfall Erosivity ◽  
Fall Velocity ◽  
Rainfall Simulator ◽  
Spatial Homogeneity ◽  
Erosion Processes ◽  
Natural Rainfall

A portable rainfall simulator was built for assessing runoff and soil erosion processes at interrill scale. Within this study, requirements and constraints of the rainfall simulator are identified and discussed. The focus lies on the calibration of the simulator with regard to spatial rainfall homogeneity, rainfall intensity, drop size, drop fall velocity and rainfall kinetic energy. These parameters were obtained using different methods including a Laser Precipitation Monitor. A detailed presentation of the operational characteristics is given. The presented rainfall simulator setup featured a rainfall intensity of 45.4 mm·h-1 with a spatial homogeneity of 80.4% based on a plot area of 0.64 m². Because of the comparatively low drop height (2 m), the diameter-dependent terminal fall velocity (1.87 m·s-1) was lower than benchmark values for natural rainfall. This conditioned also a reduced rainfall kinetic energy (4.6 J·m-2·mm-1) compared to natural rainfall with same intensity. These shortfalls, a common phenomenon concerning portable rainfall simulators, represented the best possible trade-off between all relevant rainfall parameters obtained with the given simulator setup. Field experiments proved that the rainfall erosivity was constant and replicable.

scholarly journals Measurement and computation of kinetic energy of simulated rainfall in comparison with natural rainfall.

2018 ◽  
Author(s):  
Petrů Jan ◽  
Kalibová Jana
Keyword(s):  
Kinetic Energy ◽  
Drop Size ◽  
Rainfall Intensity ◽  
Soil Aggregates ◽  
Meteorological Parameter ◽  
Simulated Rainfall ◽  
Fall Velocity ◽  
Rainfall Simulator ◽  
Rainfall Characteristics ◽  
Natural Rainfall

Rainfall characteristics such as total amount and rainfall intensity (I) are important inputs in calculating the kinetic energy (KE) of rainfall. Although KE is a crucial indicator of the raindrop potential to disrupt soil aggregates, it is not a routinely measured meteorological parameter. Therefore, KE is derived from easily accessible variables, such as I, in empirical laws. The present study examines whether the equations which had been derived to calculate KE of natural rainfall are suitable for the calculation of KE of simulated rainfall. During the experiment presented in this paper, the measurement of rainfall characteristics was carried out under laboratory conditions using a rainfall simulator. In total, 90 measurements were performed and evaluated to describe the rainfall intensity, drop size distribution and velocity of rain drops using the Thies laser disdrometer. The duration of each measurement of rainfall event was 5 minutes. Drop size and fall velocity were used to calculate KE and to derive a new equation of time-specific kinetic energy (KE<sub>time</sub> – I). When comparing the newly derived equation for KE of simulated rainfall with the six most commonly used equations for KE<sub>time</sub> – I of natural rainfall, KE of simulated rainfall was discovered to be underestimated. The higher the rainfall intensity, the higher the rate of underestimation. KE of natural rainfall derived from theoretical equations exceeded KE of simulated rainfall by 53–83% for I = 30 mm/h and by 119–275% for I = 60 mm/h. The underestimation of KE of simulated rainfall is probably caused by smaller drops formed by the rainfall simulator at higher intensities (94% of all drops were smaller than 1 mm), which is not typical of natural rainfall.  

scholarly journals Energetics of mesoscale cell turbulence in two-dimensional monolayers

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Shao-Zhen Lin ◽  
Wu-Yang Zhang ◽  
Dapeng Bi ◽  
Bo Li ◽  
Xi-Qiao Feng
Keyword(s):  
Kinetic Energy ◽  
Tumor Metastasis ◽  
Cell Types ◽  
Boltzmann Distribution ◽  
Scaling Exponent ◽  
Biological Processes ◽  
Two Dimensional ◽  
Cell Monolayers ◽  
Wide Range ◽  
Epithelial Cell Monolayers

AbstractInvestigation of energy mechanisms at the collective cell scale is a challenge for understanding various biological processes, such as embryonic development and tumor metastasis. Here we investigate the energetics of self-sustained mesoscale turbulence in confluent two-dimensional (2D) cell monolayers. We find that the kinetic energy and enstrophy of collective cell flows in both epithelial and non-epithelial cell monolayers collapse to a family of probability density functions, which follow the q-Gaussian distribution rather than the Maxwell–Boltzmann distribution. The enstrophy scales linearly with the kinetic energy as the monolayer matures. The energy spectra exhibit a power-decaying law at large wavenumbers, with a scaling exponent markedly different from that in the classical 2D Kolmogorov–Kraichnan turbulence. These energetic features are demonstrated to be common for all cell types on various substrates with a wide range of stiffness. This study provides unique clues to understand active natures of cell population and tissues.

Rainfall intensity–kinetic energy relationships: a critical literature appraisal

2002 ◽  
Vol 261 (1-4) ◽  
pp. 1-23 ◽  
Author(s):  
A.I.J.M van Dijk ◽  
L.A Bruijnzeel ◽  
C.J Rosewell
Keyword(s):  
Kinetic Energy ◽  
Rainfall Intensity ◽  
Energy Relationships ◽  
Critical Literature

scholarly journals Surface kinetic energy transfer in surface quasi-geostrophic flows

2008 ◽  
Vol 604 ◽  
pp. 165-174 ◽  
Author(s):  
XAVIER CAPET ◽  
PATRICE KLEIN ◽  
BACH LIEN HUA ◽  
GUILLAUME LAPEYRE ◽  
JAMES C. MCWILLIAMS
Keyword(s):  
Kinetic Energy ◽  
Surface Velocity ◽  
Small Scale ◽  
Surface Dynamics ◽  
Spectral Flux ◽  
Advection Term ◽  
Wide Range ◽  
Geostrophic Flows ◽  
Scale Range ◽  
Density Variance

The relevance of surface quasi-geostrophic dynamics (SQG) to the upper ocean and the atmospheric tropopause has been recently demonstrated in a wide range of conditions. Within this context, the properties of SQG in terms of kinetic energy (KE) transfers at the surface are revisited and further explored. Two well-known and important properties of SQG characterize the surface dynamics: (i) the identity between surface velocity and density spectra (when appropriately scaled) and (ii) the existence of a forward cascade for surface density variance. Here we show numerically and analytically that (i) and (ii) do not imply a forward cascade of surface KE (through the advection term in the KE budget). On the contrary, advection by the geostrophic flow primarily induces an inverse cascade of surface KE on a large range of scales. This spectral flux is locally compensated by a KE source that is related to surface frontogenesis. The subsequent spectral budget resembles those exhibited by more complex systems (primitive equations or Boussinesq models) and observations, which strengthens the relevance of SQG for the description of ocean/atmosphere dynamics near vertical boundaries. The main weakness of SQG however is in the small-scale range (scales smaller than 20–30 km in the ocean) where it poorly represents the forward KE cascade observed in non-QG numerical simulations.

Research of the Chlorine Sorption Processes when its Deposition by Water Aerosol

2021 ◽  
Vol 1038 ◽  
pp. 361-373
Author(s):  
Maksym Kustov ◽  
Andriy Melnychenko ◽  
Dmytro Taraduda ◽  
Alla Korogodska
Keyword(s):  
Sodium Hydroxide ◽  
Water Flow ◽  
Experimental Verification ◽  
Sorption Process ◽  
Water Aerosol ◽  
Sorption Model ◽  
Laboratory Facility ◽  
Wide Range ◽  
Hazardous Gases ◽  
Experimental Laboratory

Modified stepwise model of gas sorption process with finely dispersed water flow. The sorption model allows forecasting the intensity of hazardous gases deposition with adequate for the emergency recovery conditions accuracy using minimum input parameters. This allows using the sorption model under the conditions of emergency and increasing the forecasting promptness. Use of chemical neutralizer is proposed to increase the effectiveness of chlorine hazardous gas deposition. Use of sodium hydroxide is proposed as the chlorine chemical neutralizer, which is easily dissolved in water, non-toxic and easy to store. An experimental laboratory facility was developed and created with the purpose of experimental verification of the sorption processes, which allows researching the sorption processes by liquid aerosols within a wide range of dispersity. Adequacy of the existing models as well as the modified one was verified experimentally. The verification results showed a 5% indicator of the theoretical and experimental results compliance.

scholarly journals The Modelling, Simulation and FPGA-Based Implementation for Stepper Motor Wide Range Speed Closed-Loop Drive System Design

Machines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 56 ◽  
Author(s):  
Chiu-Keng Lai ◽  
Jhang-Shan Ciou ◽  
Chia-Che Tsai
Keyword(s):  
Embedded System ◽  
High Speed ◽  
Closed Loop ◽  
Open Loop ◽  
Drive System ◽  
Stepper Motor ◽  
Motor Drive ◽  
Digital Controllers ◽  
Loop Control ◽  
Wide Range

Owing to the benefits of programmable and parallel processing of field programmable gate arrays (FPGAs), they have been widely used for the realization of digital controllers and motor drive systems. Furthermore, they can be used to integrate several functions as an embedded system. In this paper, based on Matrix Laboratory (Matlab)/Simulink and the FPGA chip, we design and implement a stepper motor drive. Generally, motion control systems driven by a stepper motor can be in open-loop or closed-loop form, and pulse generators are used to generate a series of pulse commands, according to the desired acceleration/run/deceleration, in order to the drive system to rotate the motor. In this paper, the speed and position are designed in closed-loop control, and a vector control strategy is applied to the obtained rotor angle to regulate the phase current of the stepper motor to achieve the performance of operating it in low, medium, and high speed situations. The results of simulations and practical experiments based on the FPGA implemented control system are given to show the performances for wide range speed control.

scholarly journals Modelling Effects of Rainfall Patterns on Runoff Generation and Soil Erosion Processes on Slopes

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2221
Author(s):  
Qihua Ran ◽  
Feng Wang ◽  
Jihui Gao
Keyword(s):  
Soil Erosion ◽  
Rainfall Intensity ◽  
Temporal Patterns ◽  
Runoff Generation ◽  
Slope Length ◽  
Erosion Processes ◽  
Total Runoff ◽  
Wide Range ◽  
Critical Slope ◽  
Rainfall Patterns

Rainfall patterns and landform characteristics are controlling factors in runoff and soil erosion processes. At a hillslope scale, there is still a lack of understanding of how rainfall temporal patterns affect these processes, especially on slopes with a wide range of gradients and length scales. Using a physically-based distributed hydrological model (InHM), these processes under different rainfall temporal patterns were simulated to illustrate this issue. Five rainfall patterns (constant, increasing, decreasing, rising-falling and falling-rising) were applied to slopes, whose gradients range from 5° to 40° and projective slope lengths range from 25 m to 200 m. The rising-falling rainfall generally had the largest total runoff and soil erosion amount; while the constant rainfall had the lowest ones when the projective slope length was less than 100 m. The critical slope of total runoff was 15°, which was independent of rainfall pattern and slope length. However, the critical slope of soil erosion amount decreased from 35° to 25° with increasing projective slope length. The increasing rainfall had the highest peak discharge and erosion rate just at the end of the peak rainfall intensity. The peak value discharges and erosion rates of decreasing and rising-falling rainfalls were several minutes later than the peak rainfall intensity.

scholarly journals ANALISIS BANJIR KELURAHAN TANJUNG DUREN SELATAN

2020 ◽  
Vol 3 (3) ◽  
pp. 569
Author(s):  
Natanael Tadeus Sutanto ◽  
Wati Asriningsih Pranoto
Keyword(s):  
Water Resources ◽  
Natural Disasters ◽  
Water Flow ◽  
Channel Capacity ◽  
Rainfall Intensity ◽  
Chi Square ◽  
Channel Condition ◽  
Direct Measurements ◽  
Kolmogorov Smirnov ◽  
City Water

Flood is one of the natural disasters that occur due to various factors and causes many losses. Tanjung Duren Selatan village was recorded as having floods in January 2020. This research aims to determine the causes of the flood in the area as well as the solution. The data obtained were taken from BMKG, West Jakarta City Water Resources Department, and direct measurements in the review area. This research analyzed rainfall, channel capacity, channel condition dan topography in Tanjung Duren Selatan village. Rainfall is tested for data compatibility using Chi-Square and Kolmogorov-Smirnov methods. Rainfall intensity is calculated using the Mononobe formula. The capacity of the existing channels is analyzed using Manning formula that will be compared with the planned discharge calculated using Rasional method. The analysis included secondary channels and tertiary channels, based on the calculation of 8 of the 48 channels reviewed that were unable to accommodate the planned discharge. After the analysis, it can be concluded that the flooding in Tanjung Duren Selatan village was caused by the lack of existing channel capacity, contours, and rubbish that blocked the water flow. Floods that occurred on January 1, 2020 due to rainfall that occurred exceeded the planned rainfall.ABSTRAKBanjir merupakan salah satu bencana alam yang terjadi akibat berbagai faktor dan menimbulkan banyak kerugian. Di Kelurahan Tanjung Duren Selatan tercatat mengalami banjir pada bulan Januari 2020. Penelitian ini bertujuan untuk mengetahui faktor penyebab terjadinya banjir pada daerah tersebut serta solusinya. Data-data yang didapat diambil dari BMKG, Suku Dinas Sumber Daya Air Kota Jakarta Barat, serta pengukuran langsung di daerah tinjauan. Pada penelitian ini dianalisis curah hujan, kapasitas saluran, kondisi saluran, serta topografi di Kelurahan Tanjung Duren Selatan. Curah hujan di uji kecocokan datanya menggunakan metode Chi-Square dan Kolmogorov-Smirnov. Intensitas curah hujan di hitung menggunakan rumus Mononobe. Kapasitas saluran eksisting di analisis menggunakan rumus Manning yang akan dibandingkan dengan debit rencana yang dihitung menggunakan metode Rasional. Analisis yang dilakukan mencakup saluran sekunder dan saluran tersier, berdasarkan perhitungan 8 dari 48 saluran yang ditinjau tidak mampu menampung debit rencana. Setelah analisis dilakukan dapat disimpulkan bahwa banjir di Kelurahan Tanjung Duren Selatan disebabkan oleh kurangnya kapasitas saluran eksisting, kontur, serta sampah yang menghalangi aliran air. Banjir yang terjadi pada tanggal 1 Januari 2020 dikarenakan curah hujan yang terjadi melebihi curah hujan rencana.

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