Novel construction of hybrid wind turbine with solar panels: A comprehensive analysis through experimental study and numerical simulation

Experimental investigation on minimizing degradation of solar energy generation for photovoltaic module by modified damping systems

Due the movement of the sun throughout the day, the insolation level incident on the fixed panel surface varies largely. The maximum level of insolation occurs only around noon. This leads to the panel to be under-utilised. To maximise the utilisation of the panel during the day, mechanical solar tracking is used. This method not only increases the utilisation of the, but increases the power being extracted from the panel. Solar tracking using one axis tracking increases the energy yield from the solar panel by 40 percent.Extended AbstractDuring the span of a day the sun's movement has been shown in figure 1. As the day passes by, the level of incident solar radiation (insolation) changes. This change takes place due to position of the sun. The angle at which the sun's rays fall on the photovoltaic panel affects the insolation level available for the panel to convert into electrical energy. For the fixed panel, the sun's rays are not normal to plane of the panel most of the time. This causes the panel to be under-utilised. To extract more energy from the same panel, solar tracking is required. This follows the sun's movement thereby increasing the insolation level throughout the day. This increase in the insolation level is due to the fact that the angle between the normal to the solar panel and incident light is to be kept minimum. Figure 1: Sun's movement throughout the day The principle of a single axis solar tracking has been shown in figure 2. The solar tracking can be accomplished by four methods: active tracking, passive tracking, chronological tracking and manual tracking [1]. Active trackers measure the light intensity from the sun using light sensors which give signal to the controller and driving mechanism. Passive trackers commonly make use of a low boiling point compressed gas. This gas is filled in two canisters each placed in east and west directions. The heating of the fluids cause the panel to tilt over to the side with more sunshine. These will have viscous dampers to prevent excessive motion in response to wind gusts [2]. A chronological tracker uses a rotation mechanism to counteract the effect of Earth's rotation. A simple rotation mechanism, turning at a constant speed of one revolution per day or 15 degrees per hour, is adequate for many purposes, such as keeping a photovoltaic panel pointing within a few degrees of the Sun. This can easily be achieved by the use of a stepper motor control. Figure 2: Principle of single axis solar tracking The data for the insolation level and temperature for the whole year have been obtained from the NASA website for Aligarh and Doha [3]. The simulations have been run assuming that there is no condition of partial shading. For the purpose of simulation of energy output during the day, five solar panels of 250 Wp were taken in parallel to give a total of 1.25 kWp of power under STC. The energy outputs for the months throughout the year were obtained for two conditions: first for the fixed panel condition, and second for the panel with continuous one-axis solar tracking. The results have been compared and shown for Aligarh and Doha in Figs. 3 and 4 respectively. In Fig. 5, the percentage increase in the energy output for each month has been shown for both the cities. Figure 3: Daily energy yield from a 1.25 kWp solar array on a monthly basis in Aligarh Figure 4: Daily energy yield from a 1.25 kWp solar array on a monthly basis in Doha Figure 5: Increase in daily energy yield on a monthly basisReferences[1] B H Khan ‘Non-Conventional Energy Resources’ Tata McGraw Hill, 2009.[2] Kamala J. and Alex J., 2014, ‘Solar Tracking for Maximum and Economic Energy Harvesting’, Int. J. of Engg. and Tech, Vol. 5(6), pp 5030–5037.[3] NASA Surface meteorology and Solar Energy website: https://eosweb.larc.nasa.gov

Due to exponential growth in solar photovoltaic technology and power generation, it is common to see solar PV modules mounted on structures subjected to dynamic loading. These dynamic loads such as wind, rain, snow, base excitation, transportation and much more causes vibrations in the PV modules and deteriorate their performance. Among the various dynamic loads, Base Excitation is one of the major cause for induced vibration in PV modules. Vibration amplitude and frequency were preciously recorded at the base/mounting of PV module in the vicinity of Metro Rail. From the vibration reading it was observed that the peak frequency levels fall in 30-80 Hz range. Therefore, for harmonic response analysis of PV module it was necessary to build a shaker table which will provide the required base excitation for analysis. This paper deals with design, modelling, assembly and finite element modal and harmonic analysis of shaker table. Shaker table is divided in basic four parts, 1) base, 2) spring support, 3) electric motor with unbalanced mass and 4) mounting structure for PV module mounting. Variable speed electric motor is attached with a disc with different holes at varying distance from the center of the shaft, so as to provide multiple types of harmonic forces and frequencies. Before manufacturing, modal and harmonic analysis is performed on the shaker table plus PV module assembly in ANSYS to check whether the systems natural frequency comes near to only PV modules modal frequency range. It was observed that the shaker table natural frequencies were not in the range of PV module’s natural frequencies. This study will be useful to provide a basis for designing the clamping and mounting arrangements for the PV modules to retard its performance deterioration due to the induced vibrations.

This paper presents a modal analysis, Computational Fluid Dynamics (CFD), and harmonic response analysis for a 3D printed retractable x-ray film holder designed for a novel assistant robotic system. The x-ray film handler is more prone to wind and other external load which made it critical. Hence, optimizing the design based on simulation result is valuable. Based on harmonic response analysis, in a maximum wind load condition, it shows that there are max deformation and stress of 22mm and 0.013Mpa respectively with a resonant frequency to be near 7Hz when subjected repeatedly with the same load. In addition, compare with total length and dimension ratio of the part, deformation is still acceptable. Moreover, reinforcing the design through additional material on the frame is recommended since it is highly affected when excited with different vibration from the six-mode shape.

The sensitivity of monocrystalline solar module towards dust accumulation and cloud cover is investigated from May to August 2015 for Niamey’s environment. Two solar modules with the same characteristics have been used to assess the impacts of the dust on the solar PV module. One of the modules is being cleaned every morning and the second one was used for monitoring the effect of dust accumulation onto the surface of the unclean module for May and June. Results show that dust accumulation has a great effect on decreasing the daily energy yield of the unclean module. But this effect is a long-term effect. For the cloud cover, the effect is immediate. It was estimated that exposing the module into the environment in 23 days in June 2015 has reduced the daily energy yield by 15.29%. This limitation makes solar PV an unreliable source of power for remote devices and thus strongly suggests the challenges of cleaning the module’s surface regularly.

The manufacturer of an ultrasonic cleaning tank (UCT) received advise from a customer to seek the cause to why the UCT could not clean their products effectively and develop a novel UCT to replace the conventional model. This UCT had a capacity of 10 L, a frequency of 28 kHz, four horn transducers, and a total power of 200 W. To resolve that problem and respond to customers’ needs, we presented new methods to develop the UCT using the harmonic response analysis (HRA) and computational fluid dynamics (CFD) to simulate the cleaning process which occurred within the UCT based on the actual conditions. Results from the HRA showed that the acoustic pressure in a problematic UCT was low, resulting in a smaller cleaning area, which was consistent with the results from the foil corrosion test, and thus caused the cleaning process to be ineffective. We developed a novel UCT with improved effectiveness by adjusting the design and adding a water circulation system. From the HRA, we were able to design the dimensions of the UTC and position of the transducer to be suitable to increase the acoustic pressure and cleaning area. CFD results enabled us to design proper inlet and outlet shapes, as well as simulate the water flow behavior to find the optimal cleaning condition so the novel UCT had a water circulation system that could eliminate the excess particles.

Objectives: A Two Degree of Freedom parallel manipulator is used in many industries due its high payload to weight ratio, high dynamic capabilities and structural rigidity. The natural frequency is determined based on stiffness dynamic model. Methods: The stiffness matrix and mass matrix was derived, and the structural dynamics is modeled. A MATLAB code has been developed to obtain stiffness modelling and dynamic modelling equations. Design and simulation of a two DOF parallel manipulator is done by using CATIA V5 R20 software. Modal analysis is performed in ANSYS 18.1 to find the natural frequencies and mode shapes. Convergence test is made to get accurate modal frequency results. Harmonic response analysis has been made for steady-state response of a model subjected to a load that changes harmonically. Findings: From results, it is observed that the natural frequency of the circular trajectory increases as the radius increases. Novelty/Improvement: A global frequency index is taken as objective for finding the optimal dimensions of the parallel manipulator considering circular trajectory of the end effector. Modal analysis and Harmonic analysis is done using ANSYS. Using Modal analysis mode shapes and natural frequency of the parallel manipulator is obtained. Harmonic analysis is carried out to find the frequency of the parallel manipulator at the maximum deformation. The machine should run at below this frequency to avoid the high vibrations due to resonance. Keywords: Parallel manipulator, Global frequency, Natural frequency, Modal analysis, Harmonic analysis

The adoption of large-scale solar photovoltaic (PV) energy systems is needed now more than ever, yet solar project development and construction faces unquantified risk as it relates to wind damage. Lack of research, poor research methodology, and incorrect experimental assumptions have led to questions of whether wind loads on solar panels are properly codified, understood, and mitigated for. While the simulation of wind and its interaction with structures is possible with computational fluid dynamics (CFD), accurate simulation proves computationally demanding. Herein, state-of-the-art CFD approaches and machine learning (ML) algorithms are leveraged in two separate studies to determine and predict aerodynamic wind loads on solar panels respectively. In the first study, a CFD model is validated based on experimental data and employed to investigate aerodynamic wind loading at various solar panel tilt angles. Wind loads determined from the CFD simulations are compared with those determined from recent editions of the ASCE 7 standard. From the results of the first study, code revisions and the optimal stow position of solar panels during wind events are recommended. In the second study, several RANS based CFD solutions are used to train and subsequently employ a ML model to predict velocity and pressure distributions on a solar panel. This study serves as an investigation into the integration of ML and CFD for the purpose of speeding up CFD solutions without sacrificing accuracy. Results from the second study show the effects of ML hyperparameters on solution accuracy and demonstrate the significant time-savings achievable with ML compared to CFD simulations without the integration of ML.

Finite element models are widely used in dynamic analysis of misalignment rotor, but present finite element rotor models cannot simulate the axis characteristics of angle misalignment rotor, which consistent with the one with no misalignment. For achieving the precisely modeling of angle misalignment rotor, a novel modeling method called cross-coordinate substructure modeling method is introduced to establish the model of misalignment rotor, in which different parts of rotor rotate around different axis. Based on this modeling method, the 3D solid models of angle misalignment rotor are established with the help of ANSYS, and the modal characteristics and critical speeds of the misalignment rotor are achieved through modal analysis and harmonic response analysis. The numerical simulation based on Newmark method and experiment tests is carried out to obtain the response characteristics of the rotor model under the combined action of unbalanced force and misalignment load. The results show that the modal “rotation of rotor” appears, and the more amounts of response peaks can be aroused in harmonic response analysis when the rotor occurs angle misalignment. The typical fault characteristics of angle misalignment rotor in the spectrums and orbit diagrams are generally consistent both in the numerical simulation and experiment test. The research results can provide a theoretical basis for simulation and identification of the misalignment fault in rotating machinery system.

A review on role of solar photovoltaic (PV) modules in enhancing sustainable water production capacity of solar distillation units

The effect of rubber dampers on engine’s NVH and thermal performance

The harmonic response analysis model of drillstring is established to improve borehole quality. The harmonic response laws of drillstring is discussed. Harmonic response analysis is made intensively for longitudinal vibration, including non-failure case and failure case. Position of the maximum response displacement of drillstring and the maximum response stress at corresponding position are obtained through harmonic response analysis. Absorber control measure is simulated to lower vibration amplitude of drillstring. New suggestions are put forward from the view of controlling drillstring vibration by comparing and classifying features of vibration control measures comprehensively. In course of designing drilling parameter, it is required to avoid or reduce drillstring resonance under low-order inherent frequency as much as possible and adopt targeted comprehensive control measures timely. The research result is of much significance to improve wellbore quality.

In order to avoid pipe failures affecting the operation of thermal power plants, the modal and harmonic response analysis method were carried out through the finite element software ANSYS Workbench to solve the long-term vibration of the final superheater at high temperature. Modal analysis can predict the natural frequencies of each stage of the structure and provide the frequency range for the harmonic response analysis. Then the response curve of stress to the frequency under the forced vibration was obtained on the base of harmonic response analysis, and observed the stress corresponding to the peak frequency. Furthermore, the fatigue life of the system was analyzed by the fatigue tool module in ANSYS Workbench. The results show that the fatigue safety factor of the final superheater pipe is greater than the allowed safety factor, and the fatigue life could meet the requirements for safe operation. The research results have certain reference value for further research on vibration fatigue of superheater pipelines.

This paper outlines the design and testing of a horizontal-axis tidal turbine (HATT) at a scale of 1:20, employing numerical simulations and experimental validation. The design employed an in-house code based on the Blade Element Momentum (BEM) theory. As reliable lift and drag coefficients for this scale are not present in the literature due to the low Reynolds number of the airfoil, Computational Fluid Dynamics (CFD) simulations were conducted to generate accurate polar diagrams for the NACA 4412 airfoil. The turbine was then 3D-printed and the rotor tested in a subsonic wind tunnel at various fixed rotational speeds to determine the power coefficient. Fluid dynamic similarity was achieved by matching the Reynolds number and tip-speed ratio in air to their values in water. Three-dimensional CFD simulations were also performed, yielding turbine efficiency results that agreed fairly well with the experimental data. However, both the experimental and numerical simulation results indicated a higher power coefficient than that predicted by BEM theory. The CFD results revealed the presence of radial velocity components and vortex structures that could reduce flow separation. The BEM model does not capture these phenomena, which explains why the power coefficient detected by experiments and numerical simulations is larger than that predicted by the BEM theory.

Hydrokinetic turbines represent a promising solution for renewable energy generation in low-velocity rivers where conventional hydropower systems are not technically or economically feasible. Despite increasing interest in ducted hydrokinetic turbines, experimental validation of turbines employing the NACA 4415 airfoil under low-flow river conditions remains limited. This study presents the design, computational fluid dynamics (CFD) analysis, and experimental validation of a horizontal-axis ducted hydrokinetic turbine using the NACA 4415 airfoil, specifically optimized for low-velocity river applications. Numerical simulations and field experiments were conducted for water velocities ranging from 0.89 to 1.03 m/s to evaluate turbine performance in terms of rotational speed, torque, power output, and power coefficient. The results indicate that the four-bladed ducted turbine achieved a maximum experimental power output of 67 W at a flow velocity of 1.03 m/s, corresponding to a power coefficient of 0.32. The diffuser-augmented configuration enhanced flow acceleration and rotational speed compared to theoretical predictions and numerical simulations, although performance discrepancies were observed due to hydrodynamic losses and mechanical inefficiencies. Overall, the findings demonstrate the feasibility and effectiveness of NACA 4415 ducted hydrokinetic turbines for decentralized renewable energy generation in low-flow river environments, contributing valuable experimental data for the development and optimization of small-scale hydrokinetic systems.