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Records with Keyword: Modelling
120. LAPSE:2023.23220
Frequency-Domain Nonlinear Modeling Approaches for Power Systems Components—A Comparison
March 27, 2023 (v1)
Subject: Modelling and Simulations
Keywords: harmonic analysis, harmonic balance, Modelling, nonlinearity, power systems
Harmonic simulations play a key role in studying and predicting the impact of nonlinear devices on the power quality level of distribution grids. A frequency-domain approach allows higher computational efficiency, which has key importance as long as complex networks have to be studied. However, this requires proper frequency-domain behavioral models able to represent the nonlinear voltage−current relationship characterizing these devices. The Frequency Transfer Matrix (FTM) method is one of the most widespread frequency domain modeling approaches for power system applications. However, others suitable techniques have been developed in the last years, in particular the X-parameters approach, which comes from radiofrequency and microwave applications, and the simplified Volterra models under quasi-sinusoidal conditions, that have been specifically tailored for power system devices. In this paper FTM, X-parameters and simplified Volterra approaches are compared in representing the nonline... [more]
121. LAPSE:2023.23203
Modeling and Control of a Multifunctional Three-Phase Converter for Bidirectional Power Flow in Plug-In Electric Vehicles
March 27, 2023 (v1)
Subject: Energy Systems
Keywords: battery charger, control, grid-to-vehicle (G2V), Modelling, plug-in electric vehicle (PEV), sliding mode control (SMC), three-phase bidirectional power converter, vehicle-to-grid (V2G)
A nonlinear sliding-mode controller for a three-phase converter, utilized in plug-in electric vehicles (PEVs), is proposed in this paper. The proposed controller enables the utilized converter to perform multiple functions during different operating modes of the vehicle, i.e., grid-to-vehicle (G2V) and vehicle-to-grid (V2G) modes. The bidirectional three-phase converter and the proposed controller operate as a power factor correction circuit, bridgeless boost converter, and rectifier during G2V mode (i.e., plug-in charging), and it operates as a conventional single-stage inverter during V2G mode. The stability analysis of the proposed controller is performed by defining a proper Lyapunov function. The functionality of the proposed nonlinear controller is first evaluated through simulation studies. The feasibility and effectiveness of the proposed control strategy is then validated using an industrial control card through a hardware-in-the-loop (HIL) experimental testbed.
122. LAPSE:2023.22725
A Generalized Unit Commitment and Economic Dispatch Approach for Analysing the Polish Power System under High Renewable Penetration
March 24, 2023 (v1)
Subject: Energy Policy
Keywords: economic dispatch, energy policy, energy prices, Modelling, power system, renewables, unit commitment
The achievement of carbon neutrality requires a deep transformation of the Polish power sector. This paper analyses the impact of increased electricity generation from wind and solar technologies envisaged in the newest version of the Energy Policy of Poland until 2040 on the operation of dispatchable generators in 2030. The analysis was carried out using the Model of Economic Dispatch and Unit commitment for System Analysis (MEDUSA) model, which solves a mixed integer problem related to unit commitment and economic dispatch in electrical power production. At first, the model was validated based on the real operation data from 2018. Next, five scenarios were built to analyse the operation of the system in 2030. The overall result of the study is that the safest solution from the point of view of power system stability is to extend the decommissioning of coal units of 200 and 300 MW classes, to invest in renewable energy sources (RES) according to the energy policy, to build new gas pow... [more]
123. LAPSE:2023.22517
3D Spatial Reuse of Multi-Millimeter-Wave Spectra by Ultra-Dense In-Building Small Cells for Spectral and Energy Efficiencies of Future 6G Mobile Networks
March 24, 2023 (v1)
Subject: Modelling and Simulations
Keywords: 28 GHz, 60 GHz, 6G, in-building, millimeter-wave, Modelling, small cells, spectrum reuse
The sixth-generation (6G) mobile networks are expected to operate at a higher frequency to achieve a wider bandwidth and to enhance the frequency reuse efficiency for improved spectrum utilization. In this regard, three-dimensional (3D) spatial reuse of millimeter-wave (mmWave) spectra by in-building small cells is considered an effective technique. In contrast to previous works exploiting microwave spectra, in this paper, we present a technique for the 3D spatial reuse of 28 and 60 GHz mmWave spectra by in-building small cells, each enabled with dual transceivers operating at 28 and 60 GHz bands, to enhance frequency reuse efficiency and achieve the expected spectral efficiency (SE) and energy efficiency (EE) requirements for 6G mobile networks. In doing so, we first present an analytical model for the 28 GHz mmWave spectrum to characterize co-channel interference (CCI) and deduce a minimum distance between co-channel small cells at both intra- and inter-floor levels in a multistory b... [more]
124. LAPSE:2023.22483
Future Renewable Fuel Mixes in Transport in Germany under RED II and Climate Protection Targets
March 24, 2023 (v1)
Subject: Energy Systems
With the Renewable Energy Directive 2018/2001 (RED II), adopted in December 2018, the EU is continuing the political framework for the use of renewable energy sources in the transport sector for the period from 2021 to 2030. At the same time, the German federal government has set a target of reducing greenhouse gas (GHG) emissions in the transport sector by at least 40% to 42% by 2030 compared to the 1990 GHG level. To investigate the possible effects of the European and national requirements on the German GHG quota, cost-optimal fuel mixes were modelled to achieve the GHG targets of 26 fuel options in each of the nine different scenarios. The results show clear differences between the scenarios that implement the RED II targets (including 14% renewables in transport by 2030) and those that implement the climate protection target (40−42% GHG reduction compared to 1990 by 2030). If only the minimum requirements of RED II are met, the German climate protection target is clearly missed wi... [more]
125. LAPSE:2023.22436
Modeling Dark Fermentation of Coffee Mucilage Wastes for Hydrogen Production: Artificial Neural Network Model vs. Fuzzy Logic Model
March 24, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: biohydrogen, coffee mucilage, dark fermentation, Modelling, organic waste
This study presents the analysis and estimation of the hydrogen production from coffee mucilage mixed with organic wastes by dark anaerobic fermentation in a co-digestion system using an artificial neural network and fuzzy logic model. Different ratios of organic wastes (vegetal and fruit garbage) were added and combined with coffee mucilage, which led to an increase of the total hydrogen yield by providing proper sources of carbon, nitrogen, mineral, and other nutrients. A two-level factorial experiment was designed and conducted with independent variables of mucilage/organic wastes ratio, chemical oxygen demand (COD), acidification time, pH, and temperature in a 20-L bioreactor in order to demonstrate the predictive capability of two analytical modeling approaches. An artificial neural network configuration of three layers with 5-10-1 neurons was developed. The trapezoidal fuzzy functions and an inference system in the IF-THEN format were applied for the fuzzy logic model. The qualit... [more]
126. LAPSE:2023.22337
A Novel Approach on the Unipolar Axial Type Eddy Current Brake Model Considering the Skin Effect
March 24, 2023 (v1)
Subject: Modelling and Simulations
Keywords: braking torque, eddy current brake, Modelling, skin effect
The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignores the skin effect that occurrs during operation. However this phenomenon can not be simply neglected. Therefore, this paper presents a mathematical model of braking torque for a unipolar axial type of ECB system with a non-magnetic disk, which considers the skin effects. The use of mathematical models that consider the existence of skin effects is significant in approaching the braking torque according to the actual condition. The utilization of generic calculations to the model of the ECB braking torque leads to invalid results. Hence, in this paper, the correction factor was added to improve the braking torque calculation as a comparator to the proposed equation. However, the modification and addition of the correction factor were only valid to estimate the low-speed regimes of torque, but very distant for the high-speed condition. From the comparison of calculated values using analytica... [more]
127. LAPSE:2023.22285
Life Cycle Modelling of the Impact of Coal Quality on Emissions from Energy Generation
March 23, 2023 (v1)
Subject: Environment
This paper presents a model combining the LCA (Life Cycle Assessment) of fossil fuel extraction with its quality parameters and related CO2, SO2 and dust emissions at the stage of the combustion process. The model which was developed aims to identify the environmental impact of the processes of electricity production from selected energy carriers over their whole life cycle. The model takes into account the full LCA of fossil fuel extraction (of both hard and brown coal), its enrichment and fuel production as well as the environmental impact associated with emissions introduced into the air at the stage of electricity generation based on the fuels evaluated. Such an approach allows one to determine the fuel quality parameters that affect the environmental impact of energy production based on an LCA of mining and assigns the degree of environmental impact involved in particular production processes. Overall, the results obtained based on the proposed model permit the identification and... [more]
128. LAPSE:2023.22169
Frequency Response Modelling of Transformer Windings Connected in Parallel
March 23, 2023 (v1)
Subject: Modelling and Simulations
Keywords: deformation, frequency response analysis (FRA), Modelling, transformer winding
This paper describes the approach to the frequency response modelling of transformer windings consisting of coils connected in parallel. At present, computer models are intensively developed with the aim of simulating the influence of faults on the frequency response of the active part of power transformers. Frequency response analysis (FRA) is one of the standard methods used for the assessment of the mechanical condition of a transformer’s windings and core. The interpretation of the FRA results is crucial in the diagnostics of the active part of the transformer. Proper simulations of the FRA results allow the improvement and simplification of the interpretation process of the windings’ faults. Usually only serial winding wires are simulated in computer modelling and parallel wires are simplified, leading to simulation inaccuracies. In this work, a combined electromagnetic field/network method, which includes parallel connections of the coils, is proposed. The method is based on lump... [more]
129. LAPSE:2023.22100
Analytical Modeling of Neutral Point Current in T-type Three-level PWM Converter
March 23, 2023 (v1)
Subject: Modelling and Simulations
Keywords: Modelling, neutral point current, PWM converter, T-type, three-level
Since a T-type three-level PWM converter has several intrinsic advantages, it has been researched for various applications such as grid-connected converter systems. However, it necessarily requires an additional voltage control loop for balancing the upper and the lower DC-link voltage. To satisfy this requirement, an offset voltage is widely used to provide a neutral point current without affecting other variables such as total DC-link voltage and three-phase input current. However, these methods are mostly based on the averaged value between the applied offset voltage and the neutral point voltage or current, and there is no exact analytical model. Therefore, in this paper, the exact theoretical relationship between the offset voltage and the neutral point current is analyzed. This result can be expected to be useful for an effective voltage balancing control loop design as well as the better understanding of the whole system operation. The validity of the obtained analytical model i... [more]
130. LAPSE:2023.22099
Computational Modeling of Flexoelectricity—A Review
March 23, 2023 (v1)
Subject: Modelling and Simulations
Keywords: flexoelectricity, Modelling, Numerical Methods
Electromechanical coupling devices have been playing an indispensable role in modern engineering. Particularly, flexoelectricity, an electromechanical coupling effect that involves strain gradients, has shown promising potential for future miniaturized electromechanical coupling devices. Therefore, simulation of flexoelectricity is necessary and inevitable. In this paper, we provide an overview of numerical procedures on modeling flexoelectricity. Specifically, we summarize a generalized formulation including the electrostatic stress tensor, which can be simplified to retrieve other formulations from the literature. We further show the weak and discretization forms of the boundary value problem for different numerical methods, including isogeometric analysis and mixed FEM. Several benchmark problems are presented to demonstrate the numerical implementation. The source code for the implementation can be utilized to analyze and develop more complex flexoelectric nano-devices.
131. LAPSE:2023.22059
Energy Consumption on Dairy Farms: A Review of Monitoring, Prediction Modelling, and Analyses
March 23, 2023 (v1)
Subject: Food & Agricultural Processes
The global consumption of dairy produce is forecasted to increase by 19% per person by 2050. However, milk production is an intense energy consuming process. Coupled with concerns related to global greenhouse gas emissions from agriculture, increasing the production of milk must be met with the sustainable use of energy resources, to ensure the future monetary and environmental sustainability of the dairy industry. This body of work focused on summarizing and reviewing dairy energy research from the monitoring, prediction modelling and analyses point of view. Total primary energy consumption values in literature ranged from 2.7 MJ kg−1 Energy Corrected Milk on organic dairy farming systems to 4.2 MJ kg−1 Energy Corrected Milk on conventional dairy farming systems. Variances in total primary energy requirements were further assessed according to whether confinement or pasture-based systems were employed. Overall, a 35% energy reduction was seen across literature due to employing a pastu... [more]
132. LAPSE:2023.22039
Techno-Economic and Environmental Evaluations of Decarbonized Fossil-Intensive Industrial Processes by Reactive Absorption & Adsorption CO2 Capture Systems
March 23, 2023 (v1)
Subject: Environment
Keywords: and process integration, decarbonization technologies, fossil-intensive industrial processes, Modelling, reactive absorption/adsorption CO2 capture systems, Simulation, techno-economic and environmental assessments
Decarbonization of energy-intensive systems (e.g., heat and power generation, iron, and steel production, petrochemical processes, cement production, etc.) is an important task for the development of a low carbon economy. In this respect, carbon capture technologies will play an important role in the decarbonization of fossil-based industrial processes. The most significant techno-economic and environmental performance indicators of various fossil-based industrial applications decarbonized by two reactive gas-liquid (chemical scrubbing) and gas-solid CO2 capture systems are calculated, compared, and discussed in the present work. As decarbonization technologies, the gas-liquid chemical absorption and more innovative calcium looping systems were employed. The integrated assessment uses various elements, e.g., conceptual design of decarbonized plants, computer-aided tools for process design and integration, evaluation of main plant performance indexes based on industrial and simulation r... [more]
133. LAPSE:2023.21928
Development and Experimental Validation of a Supercapacitor Frequency Domain Model for Industrial Energy Applications Considering Dynamic Behaviour at High Frequencies
March 23, 2023 (v1)
Subject: Modelling and Simulations
Keywords: capacitance, Energy Storage, ESR, experimental validation, frequency model, Modelling, supercapacitor
Supercapacitors, one of the most promising energy storage technologies for high power density industrial applications, exchange the energy mostly through power electronic converters, operating under high frequency components due to the commutation. The high frequency produces important effects on the performance of the supercapacitors in relation to their capacitance, inductance and internal resistance (ESR). These parameters are fundamental to evaluate the efficiency of this energy storage system. The aim of the paper is to obtain an accurate model of two supercapacitors connected in series (functional and extrapolated unit) to represent the frequency effects for a wide range of frequencies. The methodology is based on the definition of an appropriate equivalent electric circuit with voltage dependance, obtaining their parameters from experimental tests, carried out by means of electrochemical impedance spectroscopy (EIS) and the use of specific software tools such as EC-Lab® and Stat... [more]
134. LAPSE:2023.21810
Lab-Supported Hypothesis and Mathematical Modeling of Crack Development in the Fluid-Soaking Process of Multi-Fractured Horizontal Wells in Shale Gas Reservoirs
March 23, 2023 (v1)
Subject: Energy Systems
Keywords: fracture, gas, Modelling, shale, shut-in, soaking
The objective of this study is to develop a technique to identify the optimum water-soaking time for maximizing productivity of shale gas and oil wells. Based on the lab observation of cracks formed in shale core samples under simulated water-soaking conditions, shale cracking was found to dominate the water-soaking process in multi-fractured gas/oil wells. An analytical model was derived from the principle of capillary-viscous force balance to describe the dynamic process of crack propagation in shale gas formations during water-soaking. Result of model analysis shows that the formation of cracks contributes to improving well inflow performance, while the cracks also draw fracturing fluid from the hydraulic fractures and reduce fracture width, and consequently lower well inflow performance. The tradeoff between the crack development and fracture closure allows for an optimum water-soaking time, which will maximize well productivity. Reducing viscosity of fracturing fluid will speed up... [more]
135. LAPSE:2023.21806
Modelling and Evaluation of the Thermohydraulic Performance of Finned-Tube Supercritical Carbon Dioxide Gas Coolers
March 23, 2023 (v1)
Subject: Modelling and Simulations
Keywords: finned-tube gas cooler, Modelling, supercritical carbon dioxide, thermohydraulic performance
This paper investigates the thermohydraulic performance of finned-tube supercritical carbon dioxide (sCO2) gas coolers operating with refrigerant pressures near the critical point. A distributed modelling approach combined with the ε-NTU method has been developed for the simulation of the gas cooler. The heat transfer and pressure drop for each evenly divided segment are calculated using empirical correlations for Nusselt number and friction factor. The model was validated against test results and then used to investigate the influence of design and operating parameters on local and overall gas cooler performance. The results show that the refrigerant heat-transfer coefficient increases with decreasing temperature and reaches its maximum close to the pseudocritical temperature before beginning to decrease. The pressure drop increases along the flow direction with decreasing temperature. Overall performance results illustrate that higher refrigerant mass flow rate and decreasing finned-... [more]
136. LAPSE:2023.21593
Experiments and Modeling for Flexible Biogas Production by Co-Digestion of Food Waste and Sewage Sludge
March 22, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: co-digestion, flexible biogas production, food waste, Modelling, sewage sludge
This paper explores the feasibility of flexible biogas production by co-digestion of food waste and sewage sludge based on experiments and mathematical modeling. First, laboratory-scale experiments were carried out in variable operating conditions in terms of organic loading rate and feeding frequency to the digester. It is demonstrated that biogas production can achieve rapid responses to arbitrary feedings through co-digestion, and the stability of the anaerobic digestion process is not affected by the overloading of substrates. Compared with the conventional continuous mode, the required biogas storage capacity in flexible feeding mode can be significantly reduced. The optimum employed feeding organic loading rate (OLR) is identified, and how to adjust the feeding scheme for flexible biogas production is also discussed. Finally, a simplified prediction model for flexible biogas production is proposed and verified by experimental data, which could be conveniently used for demand-orie... [more]
137. LAPSE:2023.21507
Acoustic Noise Computation of Electrical Motors Using the Boundary Element Method
March 22, 2023 (v1)
Subject: Modelling and Simulations
Keywords: acoustics, boundary element method, electric machines, finite element method, induction motors, magneto-mechanics, Modelling, noise, vibro-acoustics
This paper presents a numerical method and computational results for acoustic noise of electromagnetic origin generated by an induction motor. The computation of noise incorporates three levels of numerical calculation steps, combining both the finite element method and boundary element method. The role of magnetic forces in the production of acoustic noise is established in the paper by showing the magneto-mechanical and vibro-acoustic pathway of energy. The conversion of electrical energy into acoustic energy in an electrical motor through electromagnetic, mechanical, or acoustic platforms is illustrated through numerical computations of magnetic forces, mechanical deformation, and acoustic noise. The magnetic forces were computed through 2D electromagnetic finite element simulation, and the deformation of the stator due to these forces was calculated using 3D structural finite element simulation. Finally, boundary element-based computation was employed to calculate the sound pressur... [more]
138. LAPSE:2023.21447
Modelling of Dynamic Properties of Silicon Carbide Junction Field-Effect Transistors (JFETs)
March 22, 2023 (v1)
Subject: Modelling and Simulations
Keywords: C–V characteristics, JFET, Modelling, silicon carbide
The paper deals with the problem of modelling and analyzing the dynamic properties of a Junction Field Effect Transistor (JFET) made of silicon carbide. An examination of the usefulness of the built-in JFET Simulation Program with Integrated Circuit Emphasis (SPICE) model was performed. A modified model of silicon carbide JFET was proposed to increase modelling accuracy. An evaluation of the accuracy of the modified model was performed by comparison of the measured and calculated capacitance−voltage characteristics as well as the switching characteristics of JFETs.
139. LAPSE:2023.21442
Modeling and Enhanced Control of Hybrid Full Bridge−Half Bridge MMCs for HVDC Grid Studies
March 22, 2023 (v1)
Subject: Process Control
Keywords: average value model, hybrid MMC, Modelling, modular multilevel converter (MMC)
Modular multilevel converters (MMCs) are expected to play an important role in future high voltage direct current (HVDC) grids. Moreover, advanced MMC topologies may include various submodule (SM) types. In this sense, the modeling of MMCs is paramount for HVDC grid studies. Detailed models of MMCs are cumbersome for electromagnetic transient (EMT) programs due to the high number of components and large simulation times. For this reason, simplified models that reduce the computation times while reproducing the dynamics of the MMCs are needed. However, up to now, the models already developed do not consider hybrid MMCs, which consist of different types of SMs. In this paper, a procedure to simulate MMCs having different SM topologies is proposed. First, the structure of hybrid MMCs and the modeling method is presented. Next, an enhanced procedure to compute the number of SMs to be inserted that takes into account the different behavior of full-bridge SMs (FB-SMs) and half-bridge submodu... [more]
140. LAPSE:2023.21310
Novel Adsorption Cycle for High-Efficiency Adsorption Heat Pumps and Chillers: Modeling and Simulation Results
March 22, 2023 (v1)
Subject: Energy Systems
Keywords: adsorption cycle, adsorption system, heat recovery, Modelling, Simulation, stratified thermal storage, thermodynamic cycle
A novel thermodynamic cycle for adsorption heat pumps and chillers is presented. It shows a significant improvement of the internal heat recovery between the adsorption and the desorption half cycle. A stratified thermal storage, which allows for a temperature-based extraction and insertion of storage fluid, is hydraulically coupled with a single adsorber. The benefit is an increased efficiency by reusing the released heat of adsorption for regeneration of the adsorber and by rendering possible low driving temperature differences. For investigating the second law of this cycle, a dynamic model is employed. The transient behavior of the system and the respective losses because of driving temperature differences at the heat exchangers and losses due to mixing within the storage and to the surroundings are depicted in this one-dimensional model. The model is suitable both for analyzing this advanced cycle as well as for comparisons with other cycles.
141. LAPSE:2023.21243
Experimental Tests and Modeling on a Combined Heat and Power Biomass Plant
March 21, 2023 (v1)
Subject: Energy Systems
Keywords: combustion, Modelling, pollutant, Renewable and Sustainable Energy, woodchips
Renewable energy sources can help the countries to achieve some of the Sustainable Development Goals (SDGs) provided from the recent 2030 Agenda, allowing for clean, secure, reliable and affordable energy. Biomass technology is a relevant renewable energy to contribute to reach a clean and affordable energy production system with important emissions reduction of greenhouse gases (GHG). An innovative technological application of biomass energy consisting of a burner coupled with an external fired gas turbine (EFGT) has been developed for the production of electricity. This paper shows the results of the plant modelling by Aspen Plus environment and preliminary experimental tests; the validation of the proposed model allows for the main parameters to be defined that regulate the energy production plant supplied by woodchips.
142. LAPSE:2023.21021
Design of Diamond Power Devices: Application to Schottky Barrier Diodes
March 21, 2023 (v1)
Subject: Modelling and Simulations
Keywords: diamond, Modelling, power devices, Schottky barrier diodes, wide bandgap semiconductors
Owing to its outstanding electro-thermal properties, such as the highest thermal conductivity (22 W/(cm∙K) at room temperature), high hole mobility (2000 cm2/(V∙s)), high critical electric field (10 MV/cm) and large band gap (5.5 eV), diamond represents the ultimate semiconductor for high power and high temperature power applications. Diamond Schottky barrier diodes are good candidates for short-term implementation in power converters due to their relative maturity. Nonetheless, diamond as a semiconductor for power devices leads to specificities such as incomplete dopant ionization at room temperature and above, and the limited availability of implantation techniques. This article presents such specificities and their impacts on the optimal design of diamond Schottky barrier diodes. First, the tradeoff between ON-state and OFF-state is discussed based on 1D analytical models. Then, 2D numerical studies show the optimal design of floating metal rings to improve the effective breakdown v... [more]
143. LAPSE:2023.20940
OpenHPL for Modelling the Trollheim Hydropower Plant
March 21, 2023 (v1)
Subject: Modelling and Simulations
Keywords: hydropower, modelica library, Modelling
An increase of tightly integrated, renewable energy sources with highly varying production leads to a greater need for flexible hydropower plants to “balance” the intermittent production from these sources. From a systems perspective, the intermittency aspect constitutes a disturbance, while the tight integration leads to a multivariable systems, both of which causes increased challenges for good control. This instigates the need for a model based analysis and synthesis tool which can describe dynamic phenomena, supports multiphysics problems, and allows for immediate use in advanced control analysis and design. Previously, an open source Hydro Power Library (OpenHPL) have been developed within the multiphysics Modelica eco-system which satisfies the above requirements: OpenHPL contains a set of model units relevant for hydropower systems, as well as examples of tools for analysis of these models for control purposes. Thus far, OpenHPL has been validated by comparison against other sim... [more]
144. LAPSE:2023.20805
Reliable Tools to Forecast Sludge Settling Behavior: Empirical Modeling
March 20, 2023 (v1)
Subject: Modelling and Simulations
Keywords: Levenberg–Marquardt algorithm, Modelling, sedimentation, Vandermonde matrix, water treatment
In water- and wastewater-treatment processes, knowledge of sludge settlement behavior is a key requirement for proper design of a continuous clarifier or thickener. One of the most robust and practical tests to acquire information about rate of sedimentation is through execution of batch settling tests. In lieu of conducting a series of settling tests for various initial concentrations, it is promising and advantageous to develop simple predictive models to estimate the sludge settlement behavior for a wide range of operating conditions. These predictive mathematical model(s) also enhance the accuracy of outputs by eliminating measurement errors originated from graphical methods and visual observations. In the present study, two empirical models were proposed based on Vandermonde matrix (VM) characteristics as well as a Levenberg−Marquardt (LM) algorithm to predict temporal height of the supernatant−sludge interface. The novelty of our modeling approach is twofold: the proposed models... [more]