Damjan Ivetic | University of Belgrade (original) (raw)

Papers by Damjan Ivetic

In the Republic of Serbia, stormwater systems are managed by the municipal public utility compani... more In the Republic of Serbia, stormwater systems are managed by the municipal public utility companies. Due to the political, economic and sociological situation in the last 25 years, development was not continuous, resulting in the numerous issues that need to be addressed. Most of them are related to the socio-economic aspects, capacity building and data. Example problems and viable solutions, for achieving sustainable management by public or private utility companies, are presented through the case study of city of Pancevo

The most common method for organized solid waste disposal, in middle and low income countries, is... more The most common method for organized solid waste disposal, in middle and low income countries, is certainly the use of landfills. Although design of those structures has been improved significantly during the last decades, there are still potential hazards that require attention. In this paper, one of the many possible hazardous scenarios has been investigated. In the event of heavy precipitation leachate head is rising in the body of active landfill presuming there is no daily cover above the body. Due to leachate drainage malfunction, leachate head can rise above the design criteria value. With the landfill sidewall geomembrane previously damaged, or poorly built, gravity will drive the leachate through porous side walls of landfill. Gravity-driven groundwater flow will influence the distribution of effective stress in the body of a side wall. Effective stress, in turn, influences the potential for shear slope failure which can be quantified using the Coulomb failure potential. Fo...

Podzemne vode predstavljaju jedan od ključnih resursa za vodosnabdevanje. Matematičko modeliranje... more Podzemne vode predstavljaju jedan od ključnih resursa za vodosnabdevanje. Matematičko modeliranje dinamike podzemnih voda je neophodno u cilju sprovođenja analiza kao što su bilansiranje raspoloživih količina ili transport zagađujućih materija. Neustaljeno strujanje vode u poroznoj sredini se matematički opisuje paraboličkom, parcijalnom, diferencijalnom jednačinom drugog reda. Budući da se do analitičkog rešenja u opštem slučaju dosta teško dolazi, neophodno je pomoću neke numeričke metode doći do aproksimativnog rešenja. U ovom radu je predstavljeno postupak dobijanja numeričkog rešenja jednačine u dve dimenzije, metodom konačnih elemenata. Prednosti primene metode konačnih elemenata u numeričkom rešavanju diferencijalnih j-na su brojne, među kojima se ističu mogućnosti aproksimacije nepravilnih domena kao i diskretizacija domena mrežom promenljive gustine. Prikazan je način primene modela u sinergiji sa softverom AutoMesh 2D na primeru iz literature.

Drenažnim sistemima je neophodno oboriti nivo podzemnih voda kada postoji opasnost da ugroze rado... more Drenažnim sistemima je neophodno oboriti nivo podzemnih voda kada postoji opasnost da ugroze radove u suvom. Sniženjem NPV dolazi do porasta efektivnih napona u tlu, usled opadanja pornih pritiska, pa samim tim javlja se i sleganje tla. Za analizu sleganja tla na primeru iz prakse korišćeni su linearno elastični model tla, kao i nelinearni model sa Tercagijevim rešenjem. Sračunata su pretpostavljena sleganja primenom oba modela i ustanovljene su mere ojačanja tla kako bi se izbegla eventualna oštećenja na objektu

To quantify the hydraulic performance characteristics of hydraulic turbines several basic quantit... more To quantify the hydraulic performance characteristics of hydraulic turbines several basic quantities need to be accurately determined. Discharge, or flow rate, is the most difficult quantity to measure as the measurement uncertainty is higher and more difficult to estimate in comparison to the power and head. Design of a discharge measurement system is governed by both the geometric and flow conditions at the measurement site, as well as by the physical properties of the fluid. Moreover, in adverse or non-standard flow conditions, special care must be taken to allow for the measurement system to capture the discharge data with acceptably low measurement uncertainty. In this paper, a general description of a novel discharge measurement system, designed and installed at the Iron Gate 2 hydropower plant, is provided. The system can be installed at the turbine intake, upstream of the trash rack, on one turbine at the time. Discharge value is acquired by employing a Velocity-Area aproach. Robust steel frame, carrying 15 novel 3D electromagnetic velocity probes, along with the 2 acoustic doppler velocimeters, is traversed along the cross sectional flow area allowing for accurate velocity field mapping. Position of the traversing frame is determined with two position transducers while two pressure transducers are used for the water level measurements. The measurement system was used at two turbines at the Iron Gate 2 HPP, capturing discharge with low measurement uncertainties.

Water Resources Management

Climate change, energy transition, population growth and other natural and anthropogenic impacts,... more Climate change, energy transition, population growth and other natural and anthropogenic impacts, combined with outdated (unfashionable) infrastructure, can force Dam and Reservoir Systems (DRS) operation outside of the design envelope (adverse operating conditions). Since there is no easy way to redesign or upgrade the existing DRSs to mitigate against all the potential failure situations, Digital Twins (DT) of DRSs are required to assess system's performance under various what-if scenarios. The current state of practice in failure modelling is that failures (system's not performing at the expected level or not at all) are randomly created and implemented in simulation models. That approach helps in identifying the riskiest parts (subsystems) of the DRS (risk-based approach), but does not consider hazards leading to failures, their occurrence probabilities or subsystem failure exposure. To overcome these drawbacks, this paper presents a more realistic failure scenario generator based on a causal approach. Here, the novel failure simulation approach utilizes fuzzy logic reasoning to create DRS failures based on hazard severity and subsystems' reliability. Combined with the system dynamics (SD) model this general failure simulation tool is designed to be used with any DRS. The potential of the proposed method is demonstrated using the Pirot DRS case study in Serbia over a 10-year simulation period. Results show that even occasional hazards (as for more than 97% of the simulation there were no hazards), combined with outdated infrastructure can reduce DRS performance by 50%, which can help in identifying possible "hidden" failure risks and support system maintenance prioritization. Keywords Water resources resilience • Digital twins • Failure modes • System dynamics model Highlights • A novel method is proposed to simulate common failure situations for dam and reservoir systems. • A fuzzy-logic-based failure simulator uses hazard severity and system reliability as input. • The failure simulator provides failure magnitudes on a normalized scale. • The failure simulator is coupled with an SD model using a novel failure implementation framework. • The failure simulator coupled with an SD model provides a universal simulation tool applicable to any DRS.

Water

Dam and reservoir systems (DRSs) are crucial aspects of the infrastructure necessary for reliable... more Dam and reservoir systems (DRSs) are crucial aspects of the infrastructure necessary for reliable water resource management. Nowadays, DRSs are being increasingly affected by numerous natural and anthropogenic impacts (aging and outdated infrastructure, climate change, natural hazards, global crises, etc.). Hence, additional pressure on DRS management is being applied as DRSs must be operated in adverse operating conditions, outside of their design envelopes. Since there is no practical way to redesign DRSs to meet all possible adverse conditions, efficient simulation tools are necessary for various “what-if” analyses. A system dynamics (SD) approach can be used, as it has shown the capacity to comprehend the intrinsic system complexity. In this paper, an 11-step framework for the dynamic modelling of reduced functionality in a DRS and the emulation of the system operation in adverse conditions is proposed. The framework covers the system model design, input scenario generation, sys...

Zbornik radova Građevinskog fakulteta, 2014

Metrology in Urban Drainage and Stormwater Management: Plug and Pray, 2021

The knowledge of water levels and discharges in urban drainage and stormwater management (UDSM) s... more The knowledge of water levels and discharges in urban drainage and stormwater management (UDSM) systems is of key importance to understand their functioning and processes, to evaluate their performance, and to provide data for modelling. In this chapter, devoted mainly to underground combined and separate sewer pipe systems, various methods and technologies are described and discussed. After an introduction to important aspects to deal with when measuring discharges in sewer systems, the following parts are presented successively: (i) measurement of water level with rulers, and pressure, ultrasonic and radar sensors, (ii) measurement of flow velocity with ultrasonic, Doppler, velocity profiler, free surface, and electromagnetic sensors, (iii) direct measurement of discharge with pre-calibrated devices, physical scale models, computational fluid dynamics modelling and use of pumping stations, and (iv) detection and/or measurement of infiltration into and exfiltration from sewers, wit...

Journal of Hydroinformatics, 2015

To optimize the design of a water distribution network (WDN), a large number of possible solution... more To optimize the design of a water distribution network (WDN), a large number of possible solutions need to be examined; hence computation efficiency is an important issue. To accelerate the computation, one can use more powerful computers, parallel computing systems with adapted hydraulic solvers, hybrid algorithms, more efficient hydraulic methods or any combination of these techniques. This paper explores the possibility to speed up optimization using variations of the ΔQ method to solve the network hydraulics. First, the ΔQ method was used inside the evaluation function where each tested alternative was hydraulically solved and ranked. Then, the convergence criterion was relived in order to reduce the computation time. Although the accuracy of the obtained hydraulic results was reduced, these were feasible and interesting solutions. Another modification was tested, where the ΔQ method was used just once to solve the hydraulics of the initial network, and the unknown flow correcti...

This report describes the development of the Flushing Planning Algorithm (FPA) for deriving flush... more This report describes the development of the Flushing Planning Algorithm (FPA) for deriving flushing plans to address discolouration in drinking water distribution systems. The application of the FPA to the water system serving Amsterdam, Netherlands (Waternet), is presented.

This report summarises development and application of a modelling approach to create district met... more This report summarises development and application of a modelling approach to create district meter areas (DMAs) within a water distribution system.

Applied Sciences, 2022

The paper presents a functionality investigation of the key dam elements based on finite element ... more The paper presents a functionality investigation of the key dam elements based on finite element analysis. A detailed analysis of filtration processes, dam strength, and the surrounding rock mass was conducted. Dam elements whose potential damage could jeopardize the normal functioning of the embankment dam have been identified. A particular emphasis was placed on the analysis of dam elements that have been identified as weak points. A numerical analysis of the impact of individual grout curtain zone failure on leakage under the dam body, a strength analysis of the overflow section, as well as the analysis of the slope stability that can compromise the functioning of the spillway have been performed. To analyze the partial stability of individual structural elements, a new measure of local stability was introduced as the remaining load-bearing capacity. As a case study, the Zavoj dam, which is a part of the Pirot reservoir system in the Republic of Serbia, was used. Investigation re...

This Guidance Manual has been produced by the members of the Wat-Qual consortium, funded by the E... more This Guidance Manual has been produced by the members of the Wat-Qual consortium, funded by the European Union's Horizon 2020 research and innovation programme under grant agreement No. 778136. The manual provides a series of fact sheets covering the latest understanding of drinking water quality management in water distribution systems, covering the topics of:- flushing- disinfection- maintenance and repairs

Journal of Hydrology, 2018

Flow monitoring in Urban Drainage Systems (UDS) is required for a successful system control and o... more Flow monitoring in Urban Drainage Systems (UDS) is required for a successful system control and operational assessment. Commonly used methods can lead to erroneous results in partially filled pipes and hostile environmental conditions, normally encountered in UDS. Recent studies focused on the flow rate measurements in UDS revealed that the capability of acoustic Doppler velocimeters to estimate mean flow velocity is impeded by several factors. Most prominent issues are the operation under low flow depths and velocities, as well as in the case of the sedimentation at low flow velocities. This study is focused on an alternative method for the velocity measurements in the UDS, based on ElectroMagnetic Velocity (EMV) meters. The study also determines the sensor's capacity to operate when covered by a porous sediment layer, using a newly developed procedure. A brief theoretical background is given to support the idea behind the usage of EMV in UDS. Measurement uncertainties were firstly benchmarked in the laboratory flume without sediment. After local, sitespecific (re)calibration, EMV operated with combined uncertainty of only few cm/s. Furthermore, the EMV measured the flow rates with depths low as 4 cm and velocities bellow 5 cm/s. Additionally, a series of tests were performed with sediment layers above the EMV meter, varying in height from 0 to 80 mm. Observational uncertainty analysis showed that EMV meter can be used even in these conditions. Since the bias uncertainty increased with the rise of the sediment depth, a correction 2 function model was derived for the transformation of the output signal, reducing the observational uncertainties below 5 cm/s. Subsequently, practical implications of the EMV usage in the UDS are considered.

Procedia Engineering, 2014

Flow Measurement and Instrumentation, 2019

Abstract Flow measurements in Urban Drainage Systems (UDS) are essential for pollution control an... more Abstract Flow measurements in Urban Drainage Systems (UDS) are essential for pollution control and system management. Since the accuracy of, today the most popular, Acoustic Doppler Velocimeters is impeded by several factors, this research is focused on the alternative, or a supplemental, Electro-Magnetic Velocity (EMV) meters. EMV meters are more robust and can provide accurate low flow measurements, even when covered with porous sediment. However, the downside of EMV is the small control volume (CV) where the flow velocities are integrated in a non-linear manner to obtain a single, one-dimensional measured velocity. For a better understanding of the sensor output and measured mean flow velocity with quantified uncertainty, it is necessary to determine the size of the CV and to understand the non-linear integration principle within the CV. Valuable technical parameters, needed for describing these EMV properties, are typically not provided by the manufacturers. Fundamentally, they could be defined with the magnetic field and “virtual” current distributions. To allow for a more practical interpretation of the EMV operating principle, a simplified model of an EMV sensor is proposed here. The suggested model describes the EMV operating principle with only two technical parameters, one-dimensional weighting function w and the reach of the CV, the τ m a x . Furthermore, a methodology is proposed for defining these two parameters, using two lab flume experiments. The first one is focused on the investigation of the EMV output, when the EMV is covered by the porous sediment with different depths. The second experiment involves the determination of the longitudinal velocity distribution within the lab flume and the CV of the EMV meter. A backward analysis is suggested to formulate a minimization problem, from which the unknown technical parameters are assessed. The proposed procedure was applied on the examined Flat DC-2 EMV meter. Derived one-dimensional weighting function w exponentially drops with the distance from the electrodes, while the reach of the CV was found to be τ m a x = 8.7 cm. These parameters, and the simplified model, were validated against the EMV outputs acquired in the lab flume, without sediment presence.

To define the performance characteristics of turbines in Hydropower Plants (HPP) accurate hydraul... more To define the performance characteristics of turbines in Hydropower Plants (HPP) accurate hydraulic, mechanical and electrical quantities are needed. The discharge is the most difficult quantity to measure and assess its uncertainty (Adamkowski, 2012). Traditionally, during field acceptance tests the discharge is measured using velocity-area method. Often, no direct flow measurements are possible and only index methods are used, with flow coefficients obtained during physical model testing. In the non-standard situations, with adverse flow conditions this may lead to unpredicted flow uncertainty.

New Trends in Urban Drainage Modelling

Flow measurements in Urban Drainage Systems are essential for the pollution control. Since the ac... more Flow measurements in Urban Drainage Systems are essential for the pollution control. Since the accuracy of the Acoustic Doppler Velocimeters is impeded by several factors, this research is focused on the alternative or a supplemental ElectroMagnetic Velocity (EMV) meters. EMV meters are more robust and reliable and can provide accurate measurements of low flows or even under a porous sediment cover. However, the downside of their usage is the small control volume (CV) where the flow velocities are integrated in a nonlinear manner to obtain a single one-dimensional velocity measurement. To provide accurate mean flow velocity it is necessary to determine the size of the CV and to understand the non-linear integration principle within the CV. These valuable data are typically not provided by the manufacturer. In this paper, an experimental methodology is proposed for defining the size of the CV and the one-dimensional (1D) weighting function, used to describe the sensor's integration principle. In the experiments, bed-mounted flat DC2 EMV probe was used. The size of the CV and 1D weighting function were determined based on the results of the EMV operation under sand cover of varying depth. It was shown that the reach of the CV for the used device is 6 cm from the electrodes of the sensor.

Journal of Water Resources Planning and Management