Performance Of Mathematical Model Research Articles

New hybrid system of PV/T, solar collectors, PEM electrolyzer, and HDH for hydrogen and freshwater production: Seasonal performance investigation

A new hybrid energy system of PV/T, flat plate collector, PEM electrolyzer, and humidification-dehumidification desalination is introduced here. A comprehensive mathematical model for the system seasonal performance is constructed and solved numerically using MATLAB software. A year-round comparison between the traditional PV/T performance and its concentrated counterpart indicates that the latter performs better compared to power, hydrogen, and freshwater production and system overall efficiency. The maximum monthly achieved PV/T efficiency, electrolyzer efficiency, desalination system Gain Output Ratio, and overall system efficiency are 52 %, 62 %, 4.8 %, and 44 %, respectively at a concentration ratio of 4 and maximum allowable PV temperature. The system produces 82,200 kWh of energy annually and provides 77,700 kWh and 1500 kWh to the electrolyzer and the electric heater, respectively. Moreover, the system produces an annual freshwater production of about 52,700 kg, out of which approximately 10,000 kg are consumed in the electrolysis process, and an annual hydrogen production of approximately 1120 kg.

Mathematical modeling for the production performance of cyclic multi-thermal fluid stimulation process in layered heavy oil reservoirs

Multi-thermal fluid (MTF), with a unique thermophysical characteristics, has been widely applied in the enhanced heavy oil recovery processes. Especially for the layered heavy oil reservoirs, MTF shows more attractive than the conventional saturated steam. In this study, we propose an improved mathematical model for the production performance of cyclic MTF stimulation process in layered heavy oil reservoirs. In this model, based on a three-zone assumption, we first derive a productivity model for the thermal-fluids huff-n-puff process in layered heavy oil reservoirs. Thereafter, considering the typical EOR mechanisms of non-condensable gases in MTF, the viscosity reduction effect caused by CO2 dissolution and the effect of formation energy supplement caused by N2 are mathematically described. Simultaneously, because of the nonlinear temperature spreading behavior in the formation, an MTFs flooding experiment is also performed to characterize the effect. Meanwhile, a heating radius model with the consideration of steam overlap effect is also involved in our model. Then, the calculation results are compared against the results of a commercial simulator to confirm the accuracy, while a sensitivity analysis on the reservoir and operation parameters is performed. This paper provides a quick estimation approach for the productivity of cyclic MTF stimulation process in layered heavy oil reservoirs.

PID Controller Design for an E. coli Fed-Batch Fermentation Process System Using Chaotic Electromagnetic Field Optimization

This paper presents an optimal tuning of a proportional integral differential (PID) controller used to maintain glucose concentration at a desired set point. The PID controller synthesizes an appropriate feed rate profile for an E. coli fed-batch cultivation process. Mathematical models are developed based on dynamic mass balance equations for biomass, substrate, and product concentration of the E. coli BL21(DE3)pPhyt109 fed-batch cultivation for bacterial phytase extracellular production. For model parameter identification and PID tuning, a hybrid metaheuristic technique—chaotic electromagnetic field optimization (CEFO)—is proposed. In the hybridization, a chaotic map is used for the generation of a new electromagnetic particle instead of the electromagnetic field optimization (EFO) search strategy. The CEFO combines the exploitation capability of the EFO algorithm and the exploration power of ten different chaotic maps. The comparison of the results with classical EFO shows the superior behaviour of the designed CEFO. An improvement of 30% of the objective function is achieved by applying CEFO. Based on the obtained mathematical models, 10 PID controllers are tuned. The simulation experiments show that the designed controllers are robust, resulting in a good control system performance. The closed-loop transient responses for the corresponding controllers are similar to the estimated models. The settling time of the control system based on the third PID controller for all estimated models is approximately 9 min and the overshoot is approximately 15%. The proposed CEFO algorithm can be considered an effective methodology for mathematical modelling and achievement of high quality and better performance of the designed closed-loop system for cultivation processes.

Experimental study of the optimal mixing ratio of metallic additives for improving the performance of the solar activated carbon-methanol adsorption refrigeration system

An activated carbon–methanol system can run on low heat (70–100°C). Methanol is dependable and works well with activated carbon because of several benefits, including an appropriate latent heat of evaporation, a low freezing point, and negligible copper corrosion and steel at temperatures below 100 °C. An experimental study of the thermal performance by increasing the adsorption bed thermal conductivity was conducted. Using0 10 % 20 and %30 % of metallic copper powder with activated carbon to improve the bed thermal conductivity. A sample is prepared with 20 % copper powder to find out the improvement of heat transfer characteristics to the cooling effect. The temperature gradient has been tested with two flow rates to examine the coolant performance and increase. Solar energy can be effectively utilized based on low-grade temperature consumption in such systems. This work aims to make an experimental investigation of the thermal performance of an activated carbon-methanol adsorption refrigeration system to study the effect of the enhanced thermal conductivity of the adsorbing bed. Using 0 %, 10 %, 20 %, 30 % of metallic copper powder with activated carbon to enhance the thermal conductivity of the bed, providing a significant improvement in the system efficiency, specific cooling power (SCP), and coefficient of performance of adsorption cooling. It is found that copper filing with a mass concentration of 20 % are appeared the optimal ratio metallic additive to enhance the thermal performance of the system. Moreover, the effect of the hot water flow rate is studied. Results indicated that the addition of 20 % metallic copper filings to the activated carbon lowered the evaporator temperature to reach -5 and -10 °C for heating water flow rates 3 and 2 LPM, respectively. Also, the addition of copper filing enhances the cycle COP of the system by 49 % and 46 % at hot water flow rates of 2and 3 LPM, respectively. The highest cycle COP of the current system reached was 0.92 for the condition 20 % additives at 3 LPM hot water flow rate. Owning the feature of great solar energy availability and the long daily sunny hours, solar-powered adsorption cooling systems have promising potential applications in Egypt. A mathematical model of the system performance is also studied.

Mathematical model of explosion-proof performance of pressure container packaging based on dimension analysis

As the protective body of the pressure container, the reliability of pressure container packaging directly determines the safety of the pressure container. Therefore, the explosion-proof performance of pressure container packaging is crucial. In order to measure the explosion-proof performance of pressure container packaging, witness plate pressure is used to measure the explosion-proof performance of pressure container packaging, and a method based on dimension analysis is proposed to establish a mathematical model of the explosion-proof performance of pressure container packaging. This model quantitatively solves the nonlinear relationship between the peak pressure of the witness plate and the number of pressure container packaging layers, pressure container packaging thickness, and packaging materials. Applying this to the design of pressure container packaging can provide a reference for improving the explosion-proof performance of pressure container packaging.

Long-term performance analysis of operational efficiency of a grid-connected solar power plant under Mauritania climate

This work examines a solar power plant connected to the Nouakchott electricity grid in Mauritania. Operating since 2013, the 15 MWp plant's reliability and energy yield have been evaluated using a performance index. The assessment involves three phases. First, the plant's meteorological environment and technical indicators are presented. In the second phase, mathematical performance models specified by the International Energy Agency (IEA) are applied to calculate performance indices using data from the data acquisition system (SCADA). The third phase compares actual production data for 2015, 2017, and 2020 with results simulated for PVsyst for the same years. The obtained results are thoroughly analyzed to highlight relevant physical phenomena. The analysis focuses on the plant's 7-year operating period and its impact on performance indicators for electricity production fed into the grid. This study provides insights into the solar power plant's reliability and energy yield, aiding future operational enhancements. It underscores the importance of performance monitoring and assessment in optimizing solar power generation systems.

Mathematical modeling of reverse osmosis system design and performance

ABSTRACT Reverse osmosis (RO) is one of the most effective technologies for water desalination. However, the RO system's performance is contingent on its design parameters and operating conditions. In this study, a computational model for RO desalination performance prediction was developed. The study compares the performance parameters of the RO system utilizing various types of membranes with the established model using a single pressure vessel and seven membrane elements within the pressure vessel. This study looked at two different feed water concentrations. The first is for saltwater with a concentration of 40,000 mg/L, while the second is for seawater with a concentration of 32,000 mg/L. WAVE software assessed the findings of the generated model to the recovery ratio, feed pressure, salt rejection, and permeate concentration of each membrane element inside the pressure vessel. The results of the study show good similarity between the simulation model results and the results obtained by WAVE software as they are illustrated in Figures 4–7.

Mechanical Modeling of Viscous Fluid Damper with Temperature and Pressure Coupling Effects

During long-duration dynamic loads, such as wind loads or seismic effects, the internal temperature and pressure of a damping cylinder escalate rapidly, which induce shifts in the mechanical attributes of viscous fluid dampers (VFDs). This study investigated the mechanical performance of VFD considering the coupling effects of temperature and pressure under long-duration loads. First, we analyzed the mechanical and energy-dissipation performances of the dampers based on the dynamic mechanical tests considering different loading frequencies, displacement amplitude, and loading cycles. The experimental results indicated that both temperature and pressure influenced the output of the dampers, and in the sealed environment of the damper pip, temperature and pressure exerted mutual influence. Furthermore, the relationship between the damping coefficient and temperature–pressure coupling effects was obtained. Subsequently, an improved mathematical model for the mechanical performance of a gap-type VFD was proposed by considering the macroscopic energy balance of the entire fluid within the damper. Finally, the accuracy of the mathematical model for VFD under long-duration dynamic loads was validated by comparing the computational results with the experimental data.

Study on indoor temperature and thermal performance of a novel solar coupled floor and Kang heating system

Coupled floor and Kang surface heating terminals have significant advantages in meeting the differentiated indoor thermal requirements of Northwest rural dwellings in winter. A novel solar coupling floor and Kang surface heating system is proposed, a mathematical analysis model of thermal performance is established, and experimental validation is carried out. The solar coupling floor and Kang surface heating systems can effectively meet the differing heating requirements of indoor and bedding thermal environment. The solar fraction can reach 59.4 %, showing good energy-saving capability. The solar coupled floor and Kang surface heating system were simulated and optimized. The more suitable scheme is a solar collector size of 7.0 m2 and a water tank capacity of 0.35 m3. This configuration better meets the differing heating requirements of indoor and bedding thermal environment when the nighttime water supplier temperature is inferior to the daytime water supplier temperature. The solar coupling floor and Kang surface heating system has a 20.4 % increase and can recover the payback period in 2.3 years compared with traditional solar heating system. The results of the study support the use of solar energy to enhance the indoor thermal demands of rural dwellings in Northwest China.

Improved Mathematical Modelling and Statistical Assessment of Performance of Photovoltaic System under Non-Linear Operational Condition

It is study presents an advanced mathematical model that captures the non-linear operational characteristics of photovoltaic (PV) systems, enhancing the understanding and optimization of their performance under varying environmental conditions. By integrating principles of non-linear dynamics and statistical analysis, the model precisely simulates the performance responses of PV systems to non-linear inputs such as irradiance fluctuations, temperature variations, and load changes. We utilized a comprehensive dataset collected from multiple PV installations to validate our model, ensuring robustness and applicability. The results demonstrate a significant improvement in predicting system behaviors, which facilitates more effective management and optimization strategies. Statistical tools were employed to assess the reliability and efficiency of PV systems, revealing key insights into their operational dynamics. Our findings contribute to the development of more resilient and efficient solar energy systems, offering a valuable resource for researchers and practitioners in the field of renewable energy technologies.

Interlaminar performance of three nanomaterials film enhanced glass fiber reinforced polymer

The carbon nanotube (CNT) and graphene oxide are widely applied in Glass Fiber Reinforced Polymer (GFRP) to enhance interlaminar performance, even though they have an extremely expensive price. Herein, we provide a novel interlaminar toughening material: carbon black, which has a cheap price and good interlaminar properties. The relationship between different amounts of three nanomaterials and toughening efficiency is obtained through experiments (end notch bending (ENF) test) and the curves between different amounts and prices are revealed by the investigation. Moreover, a mathematical model of interlaminar performance, material consumption, and price is established, which can provide researchers with accurate, efficient, and inexpensive predictions in different application environments. On the other hand, a simple and efficient spraying method for making reinforcement layers is adopted in this research and we analyzed the microstructure strengthening mechanism of three nanomaterials by scanning electron microscopy (SEM).

Research on the Road Performance of Carbonaceous Mudstone Soil-Rock Mixtures under Multifactor Influence

To investigate the effects of compaction (K), rock content (RC), and wet-dry cycle (WD) on the road performance of carbonaceous mudstone soil-rock mixtures (CMSRM), orthogonal tests were designed to measure the unconfined compressive strength (UCS) and California bearing ratio (CBR). The correlation degree of K, RC, and WD with the UCS and CBR of CMSRM was investigated using orthogonal theory and grey correlation theory. Based on multivariate nonlinear regression analysis, mathematical models of the road performance of CMSRM were built. The results show that the UCS and CBR of CMSRM were positively correlated with K and negatively correlated with the WD. With increasing RC, UCS increased at first and then decreased, while CBR increased continuously. The failure modes of CMSRM change from tensile failure to shear failure as the K increases under uniaxial compression. The RC and WD affect the structural integrity of the failed samples. Combining the results of range analysis, variance analysis, and grey relational analysis, the most significant influence on the UCS is K, and the most significant influence on the CBR is RC. It is recommended to select 94%–96% for K and 40%–60% for RC in engineering.

Mathematical modeling and evaluation of permeation and membrane separation performance for Fischer–Tropsch products in a hydrophilic membrane reactor

Abstract A mathematical model was constructed to estimate the performance of an MFI-membrane reactor used for Fischer–Tropsch synthesis to produce a mixture of liquid hydrocarbons. In order to accurately evaluate the reactor’s performance a parametric study was performed. Under certain operational conditions, such as the total initial pressure in the reaction zone (1–4 MPa) and the hydrogen/carbon monoxide ratio (H2/CO: 1 to 2) on the performance of the studied reactor. The selectivity (productivity) of the hydrocarbon products (S i ), the quantity of hydrocarbons permiated (θ i ) and the separation factors of each space (α i ) were predicted. With increasing pressure, it is observed that θ CO and θ H 2 ${\theta }_{{H}_{2}}$ are decreasing from 0.62 to 0.45 and from 0.55 to 0.49 respectively. However, as the H2/CO ratio rises, this measurement shows a slight increase. Aside from, the separation factors of the majority of the current species are unaffected by the H2/CO ratio increasing, while the separation factors of carbon monoxide and hydrogen are increasing. Similarly the selectivity of water, methane, carbon dioxide and ethane increases with increasing H2/CO ratio. Based on these findings it is revealed that the membrane can enable permeability for all species present in the products mixture with varying separation factors, and that the ability to separate species other than water from the reaction side is essentially non-existent.

Limits of reactive power compensation of a doubly fed induction generator based wind turbine system

The doubly fed induction generator (DFIG) systems feature a significant amount of free power capacity that may be used for reactive power adjustment when they are put into practical use. This change, which is occasionally overlooked, is a significant one. Using DFIG systems for wind turbines (WT), this paper explored strategies for reducing and using reactive power. In order to investigate the power characteristic and how it is regulated in DFIG systems, a mathematical model for the steady-state performance of DFIG WT has been developed and presented. Here is a detailed derivation of the limiting range of DFIG's reactive power capacity as well as the physical constraints on reactive power output. The distribution of the DFIG WT at a distribution network's end is demonstrated by a simulation example. Within this simulation, reactive power management strategy, load fluctuation, and the change in wind speed are all taken into consideration. Due to the possibility of a rise in the voltage at the access point, can concluded that both acceptable and efficient to use DFIG WT's reactive power capabilities as an additional continuous reactive power source for effectiveness.

Special Issue on The Workshop on MAthematical performance Modeling and Analysis (MAMA 2023)

Special Issue on The Workshop on MAthematical performance Modeling and Analysis (MAMA 2023)

Mathematical modeling of hydrogen production performance in thermocatalytic reactor based on the intermetallic phase of Ni3Al

Mathematical modeling of hydrogen production performance in thermocatalytic reactor based on the intermetallic phase of Ni3Al

Transient modelling and simulation of a switched reluctance machine in different operating modes

An appropriate numerical computational method and simplest model captures the performance of Switched Reluctance Machines (SRMs). Several papers and computer software-based simulation models are reported in the literature. Each model has its own merits and demerits. This paper proposes a mathematical model, based on a combination of voltage and mechanical equations, suitable for the transient running of a switched reluctance machine. The simulation results of current, torque and speed profile of SRM are produced under current chopping control and voltage pulse width modulation control. The proposed work has used experimental data of flux linkage and static torque in the mathematical model for best performance and control of the machine. The obtained simulation results are verified with experimental results. This model can be extended to a range of rotor position where the machine can be switched at decreased and increased inductance region which gives motoring and generating operation mode.

An Origami Flexiball-Inspired Soft Robotic Jellyfish

Both the biomimetic design based on marine life and the origami-based design are recommended as valuable paths for solving conceptual and design problems. The insights into the combination of the two manners inspired this research: an origami polyhedra-inspired soft robotic jellyfish. The core idea of the story is to leverage the deformation mechanism of the origami metamaterial to approximate the jet-propelled swimming behavior of the prolate medusae. First, four possible variants of origami polyhedra were compared by the hydrodynamic simulation method to determine a suitable model for the soft body of robotic jellyfish. Second, the mathematical model for the jet propulsion performance of the soft origami body was built, and the diameter of the jet nozzle was determined through the simulation method. Third, the overall configuration and the rope-motor-driven driving method of the soft robotic jellyfish were presented, and the prototype was developed. The experimental work of jet swimming, thrust forces measurement, and cost of transport further demonstrated the presented soft robotic jellyfish. In addition, the prospective directions were also discussed to improve maneuverability, sensory perception, and morphological improvement. Due to the advantages, including but not limited to, the concise structure, low cost, and ease of manufacture, we anticipate the soft robotic jellyfish can serve for the ecological aquatic phenomena monitoring and data collection in the future.

A thermodynamic model of integrated liquid-to-liquid thermoelectric heat pump systems

Thermoelectric (TE) heat pumps (TEHPs) are advantageous for heating and cooling in various applications because of their modularity and simple design. A TEHP system includes the TE modules with p- and n-type materials bonded to substrates, plus heat exchangers, thermal interfaces to the heat exchangers, and heat transfer fluids. Although modeling an individual TE module has been extensively studied, limited studies have reported performance at the larger system-level. Furthermore, no prior study has addressed the impact of temperature-dependent TE material properties (e.g., electric resistivity, thermal conductivity, and Seebeck coefficient) on overall heat-pump-system-level performance. This work presents a mathematical model for TEHP system performance based on Goldsmid's approach for TE material performance, “effective” TE material properties, Gnielinski's correlation for convective heat transfer, and thermal balance theory for a heat exchange network. This combined approach provides an accurate model of the liquid-to-liquid TEHP system. Three different approaches—one empirical, one based on the manufacturer's specifications, and one drawn from the literature—were then used to determine values for TE material properties. The first two methods treated properties as constants, while the last approach treated properties as surface-temperature-based functions. Finally, experimental TEHP data was used to validate the models, all with relative absolute deviations of approximately 10% when predicting heating capacity and 10%–25% when forecasting cooling capacity up to a 30 K surface temperature lift. The results demonstrated that, at the TEHP system level, the TE material properties could be treated as constants, avoiding solver iterations and reducing the performance uncertainty by up to 95%.

Analysis of output performance of all-metal progressive cavity motor

At present, the traditional progressive cavity motor is usually a rubber stator and metal rotor, and an interference fit is set. When it encounters the high-temperature formation of 180 °C and above, the carbonization of the rubber stator causes motor failure. Therefore, the all-metal progressive cavity motor adopts a metal stator and metal rotor, and the clearance fit is installed, which has good high temperature and corrosion resistance. The leakage caused by the clearance fit is the main reason for its performance output loss. Therefore, this paper is based on the leakage mechanism of all-metal progressive cavity motor and relies on the Couette flow, Poiseuille flow, and Bernoulli's theorem. Then the mathematical model of leakage and output performance of ∅95mm all-metal progressive cavity motor is established in this paper. The 3D-surface nephogram of the model about the effects of differential pressure, density, viscosity, and clearance on motor leakage was calculated numerically and iteratively by Matlab software. At the same time, through the calculation of the motor power loss of the structure design in this paper, the power loss is smaller in the clearance range, which provides a reference for the clearance selection of this kind of motor manufacturing. Finally, according to the mathematical model of the optimal clearance of 0.3 mm in the actual working conditions, the performance curve of the numerical calculation of the motor is demonstrated through the fluid simulation. Then the performance curve is compared and verified by the experiment of the InFocus company, which provides theoretical guidance for reducing leakage of motor and improving output performance.