Analysis of Pluviograms Recorded in the Area of a Phosphogypsum Heap at Wiślinka, Poland

first_page settings Order Article Reprints Font Type: Arial Georgia Verdana Font Size: Aa Aa Aa Line Spacing:    Column Width:    Background: Open AccessConference Report Numerical Simulation of Drop Impact on Wetted and Dry Surfaces by M. GATTRINGER and H. STEINER * Institute of Fluid mechanics and Heat transfer, Graz University of Technology, Graz, Austria * Author to whom correspondence should be addressed. Sci. Pharm. 2010, 78(3), 568; https://doi.org/10.3797/scipharm.cespt.8.LPES07 Received: 12 July 2010 / Accepted: 12 July 2010 / Published: 12 July 2010 Download Download PDF Versions Notes Abstract The impact of liquid drops on wetted and dry surfaces is a complex two-phase flow phenomenon with high technical relevance especially in surface coating. [...] Share and Cite MDPI and ACS Style GATTRINGER, M.; STEINER, H. Numerical Simulation of Drop Impact on Wetted and Dry Surfaces. Sci. Pharm. 2010, 78, 568. https://doi.org/10.3797/scipharm.cespt.8.LPES07 AMA Style GATTRINGER M, STEINER H. Numerical Simulation of Drop Impact on Wetted and Dry Surfaces. Scientia Pharmaceutica. 2010; 78(3):568. https://doi.org/10.3797/scipharm.cespt.8.LPES07 Chicago/Turabian Style GATTRINGER, M., and H. STEINER. 2010. "Numerical Simulation of Drop Impact on Wetted and Dry Surfaces" Scientia Pharmaceutica 78, no. 3: 568. https://doi.org/10.3797/scipharm.cespt.8.LPES07 Find Other Styles Article Metrics No No Article Access Statistics For more information on the journal statistics, click here. Multiple requests from the same IP address are counted as one view.

To reveal the law of external pollution in the plain river network of the Taihu catchment, we investigated nitrogen, phosphorus, and dissolved organic carbon daily, as well as automatic recording data for flow rate and rainfall in Dapu River from 1st March, 2017 to 28th February, 2018. Dapu River, a typical inflowing river of Lake Taihu, usually has a reciprocating flow. A reciprocating flow is a common condition in the plain river network located in the Yangtze Delta. The response flow rate in the river was relatively slow to different intensities of rainfall. Flow rate significantly increased only when the rainfall intensity reached heavy rain (>25 mm·d-1). The concentrations were statistically non-significant under different rainfall intensities, and the concentrations of total nitrogen averaged 3.00±0.58, 3.34±0.93, 3.55±1.05, and 3.37±1.14 mg·L-1 under heavy rain (>25 mm·d-1), medium rain (10 mm·d-1-25 mm·d-1), light rain (<10 mm·d-1), and no rain. The concentrations of total phosphorus averaged 0.228±0.068, 0.258±0.121, 0.219±0.083, and 0.225±0.121 mg·L-1, respectively. The concentration of dissolved organic carbon and nitrogen in the Dapu River changed little during the 3 typical rainfall processes, but the concentration of phosphorus increased significantly after heavy rain when the duration was 2 days. The concentration of total phosphorus and particulate phosphorus increased significantly after medium rain when the duration was 1 day. The concentration of phosphorus did not show an obvious change after light rain. The concentration of total nitrogen was the highest under light rain, and the concentration of total phosphorus was the highest under medium rain. The daily loadings of total nitrogen from the Dapu River to Lake Taihu were 7.64, 3.19, 3.21, and 2.62 t·d-1 under conditions of heavy rain, medium rain, light rain, and no rain, respectively. The daily loadings of total phosphorus were 0.59, 0.26, 0.22, and 0.20 t·d-1 under conditions of heavy rain, medium rain, light rain, and no rain, respectively. Although the daily loading of nutrients under heavy rain conditions was the highest, the contribution of annual nutrient loading was small during heavy rain days. The reason was that the percentage of heavy rain during the entire year was small. The total nitrogen loading in heavy rain days was 61.11 tons in the observatory year, which was only 5.6% of annual loading. The total phosphorus loading in heavy rain days was 4.72 tons, which was only 5.8% of the annual loading. These low percentages of nutrient loading under heavy rainfall are quite different from situations in mountain catchments. This research showed that the transport processes of nutrients in the plain river network was complicated and its influence on nutrient concentrations and loadings in connected rivers was slow and indirect. The amount of inflow water was an important source of external nutrient loading in the plain river network. These conclusions have reference value for estimating the external loading and deciding non-point control policy of lakes in plain river network of the Taihu catchment.

In this study, empirical A <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</sub> -K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> and A <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> -K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> relationship-based and self-consistent methods were used to correct the attenuation of reflectivity (z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h</sub> ) and differential reflectivity (Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DR</sub> ) acquired from C- and X-bands dual-polarization radars, and the Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h</sub> of S-band Doppler radar was used to evaluate the results. The results indicated that, for Xband dual-polarization radar, the attenuation of Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h</sub> and Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DR</sub> could be corrected by two methods for heavy and moderate rain, and the distribution of Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h</sub> -Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DR</sub> scatters were closer to the theoretical relationship after self-consistent correction than that after empirical A <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</sub> -K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> and A <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> -K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> relationship-based correction. For light rain, similar results were obtained for two methods. For C-band dual-polarization radar, the degree of attenuation was less than X-band dual-polarization radar for the same intensity of rainfall, and the attenuation was need to be considered in heavy and moderate rain. For heavy rain, the distribution of Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h</sub> -Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DR</sub> scatters were closer to the theoretical relationship after empirical A <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</sub> -K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> and A <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> -K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> relationship based correction than that after self-consistent correction. For moderate rain, similar results were obtained for two methods. The corrected reflectivity of C-band dual-polarization radar was closer to that of S-band Doppler radar, however, for X-band dual-polarization radar, it was 5.10 dB larger than that of S-band Doppler radar in heavy rain, 4.64 dB in moderate rain, and 3.34 dB in light rain. It was consistent with the scattering simulation results of other scholars.

Both experiment and numerical simulation of bird impact on aircraft windshield was studied. The finite element model of bird impact on the windshield was established to predict the damage initiation and propagation of the windshield after bird impact via the nonlinear finite element method, combined with the user-defined materials subroutine (VUMAT) of the ABAQUS/Explicit software. In the model, an elastic-plastic and a nonlinear viscoelasticity constitutive model were adopted to define the material constitutive response of bird and windshield, respectively. The shear failure criteria and the tensile failure were selected to identify the damage of bird and windshield, respectively. The corresponding elements will be removed when the materials meet the above failure criteria. The supporting structure of the windshield glass was modeled with skins and rubber gaskets herein instead of modeled with the boundary condition directly. The analysis results include the instantaneous deformation of bird and windshield, the damage modes of the windshield, displacement curves and strain curves of the measured points on the windshield, which agree well with the experimental results. I. Introduction HE bird impact against aircraft structures can cause catastrophic damages. The statistical data shows that the probability of the windshield and cockpit impacted by birds is about 21.4%, which is the biggest probability comparing with the other parts of the aircraft. The records also present that the impacted windshield and cockpit are much more dangerous than the other parts. It is unpractical to avoid the bird-strike accident, but important to take into account the windshield’s capability against bird-strike. It is necessary to carry out the full-scale bird-strike experiments in order to determine the degree of damage after bird-strike, to evaluate the dynamic failure position for the windshield and to obtain the critical speed of the bird for the structure configuration, support boundary and material properties of the windshield in a structural design. The bird-strike experiment costs a lot of money and human resources, and usually, is not directly instructive to the design of the new windshield. The reason is that most of the bird impact tests only record the data measured from some specific surface points on the windshield specimens rather than the total deformation response, especially, the instantaneous failure characteristics of the structure during the impact process. With the rapid development of computer and finite element method, the numerical analysis has been increasingly adopted to analyze bird impacts at locations and in conditions without considered in the experimental tests, as well as to evaluate the effectiveness of design modifications to improve the structural response and even for simulations on design hypotheses, before carrying out any preliminary test. In the paper, both experiment and numerical simulation of bird impact on aircraft windshield are presented. The numerical simulation is carried out based on ABAQUS/Explicit, a nonlinear finite element program. In the simulation, the bird adopts an elastic-plastic model with shear failure, verified in this paper with an instance in the other literature. The windshield is modeled in a nonlinear viscoelasticity constitutive material, which is implemented by the user-defined subroutine VUMAT within ABAQUS/Explicit. A comparison between the simulation results and the experiment data shows a good agreement.

The 2019/2020 floods in the <scp>UK</scp>: a hydrological appraisal

There are increasing efforts towards the prediction of high-impact weather systems and understanding of related dynamical and physical processes. High-resolution numerical model simulations can be used directly to model the impact at fine-scale details. Improvement in forecast accuracy can help in disaster management planning and execution. National Centre for Medium Range Weather Forecasting (NCMRWF) has implemented high-resolution regional unified modeling system with explicit convection embedded within coarser resolution global model with parameterized convection. The models configurations are based on UK Met Office unified seamless modeling system. Recent land use/land cover data (2012–2013) obtained from Indian Space Research Organisation (ISRO) are also used in model simulations. Results based on short-range forecast of both the global and regional models over India for a month indicate that convection-permitting simulations by the high-resolution regional model is able to reduce the dry bias over southern parts of West Coast and monsoon trough zone with more intense rainfall mainly towards northern parts of monsoon trough zone. Regional model with explicit convection has significantly improved the phase of the diurnal cycle of rainfall as compared to the global model. Results from two monsoon depression cases during study period show substantial improvement in details of rainfall pattern. Many categories in rainfall defined for operational forecast purposes by Indian forecasters are also well represented in case of convection-permitting high-resolution simulations. For the statistics of number of days within a range of rain categories between ‘No-Rain’ and ‘Heavy Rain’, the regional model is outperforming the global model in all the ranges. In the very heavy and extremely heavy categories, the regional simulations show overestimation of rainfall days. Global model with parameterized convection have tendency to overestimate the light rainfall days and underestimate the heavy rain days compared to the observation data.

The Johnstown Flood of May 31, 1889, was responsible for more recorded deaths than any other disaster in the United States until the Galveston hurricane of 1900.1 An important difference between the two is that the Johnstown flood was not a natural disaster. Although the Johnstown region was in the midst of a particularly wet spring and the former boroughs that now form the city of Johnstown were already experiencing low-level flood-ing on May 31, the ultimate reason for the high death toll was the catastrophic failure of the South Fork Dam, located fourteen miles upstream from the outskirts of Johnstown on the South Fork of the Little Conemaugh River (see fig. 1). The millions of tons of water released by the failure of the dam caused devastation along the Little Conemaugh River drainage. As the water moved downstream it was temporarily impounded by debris dams behind two Pennsylvania Railroad bridges (Viaduct and Bridge no. 6), which caused "reformation of the lake" at these points. When Bridge no. 6 failed, the rejuvenated flood wave sped toward Johnstown. Most structures

This paper focuses on investigating the effects of different rainfall intensities on traffic operations of urban road networks. Macroscopic Fundamental Diagram (MFD) and Spearman correlation coefficient are used to quantitatively describe the network's operation and measure the rainfall impact on it. Mastering the rainfall impact on urban road traffic operation is not only important for the traffic state evaluation in rainy days, but also for the development of effective management strategies under rainy conditions. An empirical analysis is carried out on a major arterial network located on Haizhu district of Guangzhou, China. The results indicate that the rainfall events increased the uncertainty in network performance, and the reduction is in an increasing tendency with the increase in rainfall intensity. Furthermore, the different rainfall intensities have divergent impacts on macroscopic traffic variables. The heavy rain and rainstorm have remarkable negative effect on macroscopic traffic parameters, which produced Critical Accumulation and Maximum Production reduction of 10.5%, 16.7% and 21.0%, 18.7%, respectively. While the light rain and moderate rain have relative small impact on network's operation. What's more, the precipitation resulted in a significant decrease effect on the parameters of weighted free-flow speed and weighted jam density of the study network, the average reduction is 9.7% and 12.3%, regardless of the intensity. The production and weighted speed are also reduced by rainy condition, but the parameter of accumulation is not rainy-sensitive.

The global increase in temperature due to climate change is affecting regional hydrological cycles, resulting in an increase in the frequency and intensity of extreme rainfall in certain areas. South Korea is also experiencing more frequent localized heavy rainfall within short periods due to global warming. In response, the Korea Meteorological Administration (KMA) operates a two-stage heavy rain advisory/warning system to minimize damage during heavy rainfall and effectively respond to expected rainfall. The heavy rain advisory is issued when cumulative rainfall of 60mm (110mm) is expected over 3 hours (12 hours), while the heavy rain warning is issued when cumulative rainfall exceeds 90mm (180mm) over the same periods. However, the impact of heavy rainfall varies by region, depending on local characteristics such as infrastructure, geographical location, and topography. Currently, the heavy rain advisories/warnings apply uniform standards nationwide, which do not take into account regional characteristics.Therefore, to enhance the effectiveness of the heavy rain advisory/warning system, it is essential to establish region-specific criteria that reflect regional rainfall characteristics and local factors (such as damage, topography, and soil). To this end, the KMA is conducting research to develop differentiated heavy rain advisory/warning standards for each region. This study analyzes regional damage characteristics related to rainfall by utilizing recent meteorological and damage data, considering the increasing spatial concentration of heavy rainfall and its intensity. Using cluster analysis techniques, the study identifies regions with similar characteristics in terms of rainfall frequency, damage frequency, and topographical features, and aims to provide supporting data for setting region-specific heavy rain advisory/warning standards. The data used in this study include rainfall observation data (3-hour and 12-hour cumulative) from 712 KMA AWS stations from 2016 to 2022, as well as heavy rainfall damage data from the Ministry of the Interior and Safety's Disaster Yearbook and the National Disaster Management System (NDMS). The K-means clustering method, which assigns data to the closest cluster center, was employed to determine the optimal number of clusters.

The note gives the results of an analysis of the rainfall recorded in fifteen minute periods at Madras from the records of the Casella siphon raingauge during the years 1932 to 1947.&#x0D; There is rain in Madras both during the southwest monsoon from June to September and during the northeast monsoon from October to January. During the former season, on many of the rainy days there 18 only a single spell of rainfall and there are very few days when rainfalls more than thrice. The spells are generally of short duration.-less than an hour The rainfall is of low intensity, under 25 cents per hour, Mostly, and there are very few occasion when the intensity exceeds100 cents per hour. Such heavy rains as do occur have a tendency to do so after about 1500 IST and during the night. The maximum intensity of rainfall during rainy days is also generally attained during these hours. During the northeast monsoon, on a number of days rain occurs more than once. The spells are generally of short duration through a few of them may extend over several hours. The rainfall is of low intensity, but heavy rains occur more frequently than during the period of the southwest monsoon. Heavy rains have a tendency to occur after midnight and before early afternoon.

Raindrop size distributions (DSDs) are the main tool for describing and discussing rain microphysics. They play a crucial role in remote sensing of precipitation and extensive efforts have been devoted to measuring and modeling them. However, when it comes to DSDs in extreme rain, very few, reliable, results are available. Using numerical simulations, Srivastava (1978, 1982) and List (1988) theorized that for high enough rainfall intensities (&gt;40 mm/h), DSDs should converge toward a stationary state where drop coalescence and breakup are in dynamical equilibrium with each other. In such conditions, the shape of the DSDs should be constant and the particle number concentration should be proportional to the rain rate. However, reliable evidence of such transitions toward a &amp;#8220;number-controlled&amp;#8221; remains scarce and many researchers have contested its existence.In this study, high-quality DSD observations from a network of 7 optical disdrometers belonging to the Ruisdael observatory for Dutch atmospheric science are used to take a new, fresh look at the issue. The main research questions are:Is there empirical evidence for a transition from size to number-controlled regimes at high rainfall intensities in the Netherlands? What parametric model best fits DSDs at high rainfall rates? Can the super-CC scaling of sub-hourly rainfall extremes with temperature highlighted by Lenderink et al. (2008) be explained by changes in DSDs? To address the questions above, we analyze characteristic drop sizes (Dm, D0), number concentrations (NT, Nw) and state variables (LWC, Z, Zdr) for different classes of rainfall intensities and temperatures and study the shape of DSDs by comparing the goodness of fit of various parametric DSD models. We look at non-parametric descriptors such as the relative number of small versus large drops and study the scaling laws linking different moments of the DSD in heavy rain using single and double-normalization frameworks to assess possible convergence toward number-controlled regime at higher intensities.

In this work we present the numerical simulation results for the molten nickel and zirconia (YZS) droplets impact on different micro-scale patterned surfaces of silicon. The numerical simulation clearly showed the effect of surface roughness and the solidification on the shape of the final splat, as well as the pore creation beneath the material. The simulations were performed using a computational fluid dynamic software, Simulent Drop, The code uses a three-dimensional finite difference algorithm solving full Navier Stokes Equation with heat transfer and phase change. Volume of fluid (VOF) tracking algorithm is used to track the droplet free surface. Thermal contact resistance at the droplet– substrate interface is also included in the model. Specific attention is paid to the simulation of droplet impact under plasma spraying conditions. The droplet sizes ranged from 15 to 60 microns with the initial velocities of 70-250 m/s. The substrate surface was patterned by a regular array of cubes spaced at 1 µm and 5 µm from each other. The peak to valley height of each cube was between 1 to 3 µm. Different splat morphologies will be compared with those obtained from the experimental results under the same impact and surface conditions.

This work presents numerical simulation results for molten nickel and zirconia (YZS) droplets impacting on different microscale-patterned surfaces of silicon. The numerical simulation clearly showed the effect of surface roughness and solidification on the shape of the final splat, as well as the pore creation beneath the sprayed material. Simulations were performed using computational fluid dynamic software, SimDrop. The code uses a three-dimensional finite-difference algorithm solving the full Navier-Stokes equation, including heat transfer and phase change. A volume of fluid (VOF) tracking algorithm is used to track the droplet-free surface. Thermal contact resistance at the droplet-substrate interface is also included in the model. Specific attention is paid to the simulation of droplet impact under plasma spraying conditions. Droplet sizes ranged from 15 to 60 microns with initial velocities of 70-250 m/s. Substrate surfaces were patterned with regular arrays of cubes 1-3 μm high, spaced either 1 μm or 5 μm from each other. Different splat morphologies produced by simulations are compared with those obtained from the experiment conducted under the same impact and surface conditions.

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;New highly ductile advanced high strength steel (AHSS) grades with tensile strength greater than 980 MPa have been developed with the aim of achieving a combination of high strength and excellent formability. The new jetQ&lt;sup&gt;TM&lt;/sup&gt;-Family [&lt;span class="xref"&gt;1&lt;/span&gt;, &lt;span class="xref"&gt;2&lt;/span&gt;] offers high local and global ductility, which is expected to contribute to the improvement of vehicle crash performance.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;For the reliable design and management of vehicle crash performance, material modeling, including work hardening behavior and material failure strain, plays an important role in numerical simulation. Especially, the accuracy of material failure prediction is important for the development of crash performance.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;In this study, the fracture behaviors of 980jetQ&lt;sup&gt;TM&lt;/sup&gt;, 1180jetQ&lt;sup&gt;TM&lt;/sup&gt;, and conventional Dual-Phase (DP) steels are investigated through simple tensile and V-bending fracture tests incorporating experimental-numerical hybrid ductile fracture analysis. Based on the experimental results, the ductile fracture parameters in the Hosford-Coulomb fracture model [&lt;span class="xref"&gt;3&lt;/span&gt;] are determined for numerical crash simulation.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;To investigate the validity of the calibrated ductile fracture model, axial crushing tests of hat-shaped square columns are performed for the 980 MPa grade. Numerical simulations of axial impact are also performed by ANSYS LS-DYNA [&lt;span class="xref"&gt;4&lt;/span&gt;] under the same conditions as in the experimental tests, and three-point bending tests are carried out for the 1180 MPa grade to simulate side crash deformation. Both the numerical simulations of the axial crash and the three-point bending crash show good agreement with the experimental results.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;The developed material model can express the excellent local elongation performance of the jetQ materials. The crash simulation with the material model shows good crash performance with a low risk of fracture during crash deformation.&lt;/div&gt;&lt;/div&gt;

Seismic activity generated by impacts depends on impact conditions and properties of the impact site. Here, we combined mapping of the regolith thickness with numerical impact simulations to better estimate the seismic efficiency and seismic moment generated in small impact events in the uppermost crust on Mars. We used mapping of crater morphology to determine the regolith thickness that craters formed in. We found that local regolith thickness in the late Amazonian units is between 4 and 9 m. Combined with previous estimates for the NASA InSight landing site, we composed a more realistic uppermost crust analog and implemented it in numerical impact simulations. We estimated the seismic efficiency and seismic moment for small craters on Mars impacting a non‐porous or fractured bedrock overlaid by 5, 10, or 15 m thick regolith. Seismic energy showed more dependence on target properties. Three orders of magnitude more energy were produced in stronger targets. The seismic moment does not depend on target properties, and we confirm that seismic moment is almost proportional to impact momentum. The resulting seismic moment is in agreement up to a factor of 4 between different target types. We improved the scaling relationships developed from numerical simulations used in seismic moment approximations by constraining its dependence on more realistic target properties.