Wind Energy Conversion: The Potential of a Novel Ducted Turbine for Residential and Commercial Applications

2013 ◽  
Author(s):  
N. Goudarzi ◽  
W. D. Zhu ◽  
H. Bahari
Keyword(s):  
Mathematical Model ◽  
Wind Power ◽  
Flow Behavior ◽  
Experimental Tests ◽  
Simulation Techniques ◽  
Ducted Turbine ◽  
Grid Applications ◽  
Commercial Applications ◽  
Four Quadrant ◽  
The Mathematical Model

A novel ducted turbine, referred to as a Wind Tower, for capturing wind power in either residential or commercial scale applications is studied theoretically and experimentally. A mathematical model is developed to predict the flow behavior inside the tower and a velocity coefficient is defined to correct the results at different test conditions. A wind tower prototype, including a four-quadrant-peak wind-catcher rooftop, a tower, a nozzle, and a turbine, is designed and fabricated. The captured wind power values from the mathematical model and the preliminary experimental tests are compared. While the mathematical model provides a good estimation of the output power in some cases, more precise experimental tests and simulation techniques are required to improve the mathematical model in some other cases. Significant changes in the output wind speed due to pressure differences created by the surrounding environment, the tower height, and the number of nozzles are observed. The advantages of being maintenance free, reliable, and sustainable, together with its special design that eliminates bird/bat mortality make the Wind Tower a promising solution for residential, commercial, and even off-grid applications.

scholarly journals Passive Measurement of Three Optical Beacon Coordinates Using a Simultaneous Method

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5235
Author(s):  
Jiri Nemecek ◽  
Martin Polasek
Keyword(s):  
Mathematical Model ◽  
Relative Position ◽  
Experimental Tests ◽  
Image Sensor ◽  
Geometric Parameters ◽  
Light Sources ◽  
Feature Points ◽  
Passive Measurement ◽  
The Mathematical Model ◽  
Physical Principles

Among other things, passive methods based on the processing of images of feature points or beacons captured by an image sensor are used to measure the relative position of objects. At least two cameras usually have to be used to obtain the required information, or the cameras are combined with other sensors working on different physical principles. This paper describes the principle of passively measuring three position coordinates of an optical beacon using a simultaneous method and presents the results of corresponding experimental tests. The beacon is represented by an artificial geometric structure, consisting of several semiconductor light sources. The sources are suitably arranged to allow, all from one camera, passive measurement of the distance, two position angles, the azimuth, and the beacon elevation. The mathematical model of this method consists of working equations containing measured coordinates, geometric parameters of the beacon, and geometric parameters of the beacon image captured by the camera. All the results of these experimental tests are presented.

scholarly journals A mathematical model of common-cold epidemics on Tristan da Cunha

1971 ◽  
Vol 69 (3) ◽  
pp. 423-433 ◽  
Author(s):  
B. J. Hammond ◽  
D. A. J. Tyrrell
Keyword(s):  
Mathematical Model ◽  
Common Cold ◽  
Average Duration ◽  
Model Parameters ◽  
Epidemic Threshold ◽  
Tristan Da Cunha ◽  
Simulation Techniques ◽  
Time Courses ◽  
The Mathematical Model ◽  
Computer Simulation Techniques

SUMMARYRecords of seven common-cold outbreaks on the island of Tristan da Cunha are compared with the corresponding time courses given by the mathematical model of Kermack & McKendrick (1927) and with an alternative model that directly involves a constant average duration of individual infection. Using computer simulation techniques the latter model is shown to be preferred and is then closely matched to the field data to obtain values for the model parameters. Consideration is then given to the intensity of epidemics predicted by the model and to the distribution of the actual epidemics relative to the theoretical epidemic threshold.

Adapted Bouc-Wen Analytical Model for Romanian SERB-C Seismic Dampers Used in Buildings Protection System

2016 ◽  
Vol 823 ◽  
pp. 91-94 ◽  
Author(s):  
Adriana Ionescu ◽  
Cristian Burada ◽  
Mihai Negru
Keyword(s):  
Mathematical Model ◽  
Computational Simulation ◽  
Experimental Tests ◽  
Protection System ◽  
Hysteretic Model ◽  
Specific Adaptation ◽  
Analytical Simulation ◽  
The Mathematical Model ◽  
Force Displacement ◽  
Unusual Shape

In this paper is presented a new mathematical model which is intended to simulate the hysteretic phenomenon of SERB-C Romanian friction device for damping and dissipation of earthquake energy used for buildings. These devices have unusual shape of force-displacement loop which can be simulated with our new model which represents a specific adaptation of the well known Bouc-Wen hysteretic model. The purpose of this analytical simulation is to determine a relation for the hysteretic loop which was obtained by experimental tests performed by the authors. The mathematical model presented in this paper can be used in computational simulation of a building protected with these types of devices, in order to determine the anti-seismic performances of a Romanian friction building protection system.

Wind-driven land-yacht robot mathematical modeling and verification

2016 ◽  
Vol 43 (1) ◽  
pp. 77-90 ◽  
Author(s):  
Jiqing Chen ◽  
Shaorong Xie ◽  
Jun Luo ◽  
Hengyu Li
Keyword(s):  
Mathematical Model ◽  
Experimental Tests ◽  
Outer Planet ◽  
Mechanism Analysis ◽  
Content Type ◽  
The Antarctic ◽  
The Mathematical Model ◽  
The Given ◽  
Practical Implications ◽  
Wind Resources

Purpose – The purpose of this paper was to solve the shortage of carrying energy in probing robot and make full use of wind resources in the Antarctic expedition by designing a four-wheel land-yacht. Land-yacht is a new kind of mobile robot powered by the wind using a sail. The mathematical model and trajectory of the land-yacht are presented in this paper. Design/methodology/approach – The mechanism analysis method and experimental modeling method are used to establish a dual-input and dual-output mathematical model for the motion of land-yacht. First, the land-yacht’s model structure is obtained by using mechanism analysis. Then, the models of steering gear, servomotors and force of wing sail are analyzed and validated. Finally, the motion of land-yacht is simulated according to the mathematical model. Findings – The mathematical model is used to analyze linear motion and steering motion. Compared with the simulation results and the actual experimental tests, the feasibility and reliability of the proposed land-yacht modeling are verified. It can travel according to the given signal. Practical implications – This land-yacht can be used in the Antarctic, outer planet or for harsh environment exploration. Originality/value – A land-yacht is designed, and the contribution of this research is the development of a mathematical model for land-yacht robot. It provides a theoretical basis for analysis of the land-yacht’s motion.

scholarly journals Modeling of electricity production by wind power stations of Ukraine

2021 ◽  
Vol 280 ◽  
pp. 09010
Author(s):  
Volodymyr Podhurenko ◽  
Yulii Kutsan ◽  
Oleg Getmanets ◽  
Volodymyr Terekhov
Keyword(s):  
Mathematical Model ◽  
Wind Power ◽  
Black Sea ◽  
Energy Production ◽  
Electricity Production ◽  
Operational Parameters ◽  
Black Sea Region ◽  
Power Stations ◽  
The North ◽  
The Mathematical Model

Based on the results of actual multi-year measurements of wind speeds, numerical calculations have been made of the forecast energy productions of 43 megawatt-high power stations of the leading world producers in the wind conditions of the North Black Sea region of Ukraine. The established correlation between the annual energy production of wind power station (WPS) and its basic parameters (nameplate capacity, diameter of the rotor and hub height) allowed to develop a mathematical model of the forecast annual energy production of WPS. The calculations for the mathematical model are well in line with the operational parameters of the generation. The mathematical model makes it possible to quickly and reliably select (or design) the optimal wind turbine for industrial wind power in the North Black Sea, thus taking a significant step in reducing the energy dependency, environmental protection and the transition to energy-efficient and environmentally friendly technologies enabling Ukraine to reach the level of advanced states in the development of wind energy.

Design and Modeling of an Experimental ROV with Six Degrees of Freedom

Drones ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 113
Author(s):  
Aleksey Kabanov ◽  
Vadim Kramar ◽  
Igor Ermakov
Keyword(s):  
Mathematical Model ◽  
Degrees Of Freedom ◽  
Experimental Tests ◽  
Underwater Vehicles ◽  
Six Degrees Of Freedom ◽  
Functional Capabilities ◽  
Classical Design ◽  
Wide Range ◽  
Reduced Costs ◽  
The Mathematical Model

With the development of underwater technology, it is important to develop a wide range of autonomous and remotely operated underwater vehicles for various tasks. Depending on the problem that needs to be solved, vehicles will have different designs and dimensions, while the issues surrounding reduced costs and increasing the functionality of vehicles are relevant. This article discusses the development of inspection class experimental remotely operated vehicles (ROVs) for performing coastal underwater inspection operations, with a smaller number of thrusters, but having the same functional capabilities in terms of controllability (as vehicles with traditionally-shaped layouts). The proposed design provides controllability of the vehicle in six degrees of freedom, using six thrusters. In classical design vehicles, such controllability is usually achieved using eight thrusters. The proposed design of the ROV is described; the mathematical model, the results of modeling, and experimental tests of the developed ROVs are shown.

scholarly journals The Influence of Water and Mineral Oil on Mechanical Losses in a Hydraulic Motor for Offshore and Marine Applications

2020 ◽  
Vol 27 (2) ◽  
pp. 125-135 ◽  
Author(s):  
Paweł Śliwiński
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Mineral Oil ◽  
Hydraulic Motor ◽  
Influence Of Water ◽  
Marine Applications ◽  
The One ◽  
The Mathematical Model

AbstractIn this paper, mechanical losses in a hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted using a special design (prototype) of a hydraulic satellite motor. The design of the satellite motor is presented. This motor was developed to supply both with water and mineral oil and features a non-circular tooth working mechanism. The paper also characterizes sources of mechanical losses in this motor. On this basis, a mathematical model of these losses has been developed and presented. The results of calculation of mechanical losses according to the model are compared with the experimental results. Experimental studies have shown that the mechanical losses in the motor supplied with water are 2.8 times greater than those in the motor supplied with oil. The work demonstrates that the mechanical losses in both the motor supplied with water and the one supplied with oil are described well by the mathematical model. It has been found that for the loaded motor working at high speed, the simulation results differ from experimental ones by no more than 3% for oil and 4% for water.

scholarly journals Numerical study of a modified Trombe wall solar collector system

2009 ◽  
Vol 13 (1) ◽  
pp. 195-204 ◽  
Author(s):  
Snezana Dragicevic ◽  
Miroslav Lambic
Keyword(s):  
Mathematical Model ◽  
Numerical Study ◽  
Operational Parameters ◽  
Collector System ◽  
Fast Running ◽  
Simulation Techniques ◽  
Solar Radiation Intensity ◽  
Trombe Wall ◽  
Solar Wall ◽  
The Mathematical Model

The paper presents numerical analysis of efficiency of the modified Trombe wall with forced convection. The analyzed system comprises a double glass glazing, and a massive wall with opening and central channel in it. In order to increase the efficiency, a fan is provided at the bottom vent of the wall. It is more advanced as compared with simple Trombe solar wall with a relatively low thermal resistance, which is taken as a reference in experimental analysis. The mathematical model, composed for the massive solar wall efficiency, is usually very complicated and assessment of the thermal behavior requires the use of thermal simulation techniques. This paper presents steady-state and one-dimensional mathematical model for simplified analysis of thermal efficiency of modified Trombe solar wall. The results from presented model were analyzed to predict the effects of variations in the operational parameters on the solar wall efficiency: solar radiation intensity, air velocity in the entrance duct, and room air temperature. The results have been compared with the available experimental study, and the comparison has shown satisfactory agreement. The obtained results have be used for simple and fast running design tools that designers can use in the early phases of the design process for approximate calculations of efficiency of the passive solar heating systems.

Validation of the Mathematical and Numerical Models for Artillery Barrels Autofrettage Based on Hydrostatic Procedure

2012 ◽  
Vol 186 ◽  
pp. 58-69
Author(s):  
Ghiţă Bârsan ◽  
Silviu Mihai Petrişor ◽  
Luminiţa Giurgiu
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Numerical Models ◽  
Experimental Tests ◽  
Tension Test ◽  
Advanced Materials ◽  
New Materials ◽  
New Techniques ◽  
The Military ◽  
The Mathematical Model

The research of advanced gun barrels focuses on materials or the combination between advanced materials and new innovative processes that enable the increase of the life cycle and performances of all calibers cannons. In addition to the investigation of new materials, considerable efforts were made for developing new techniques. The paper describes a theoretical framework validated with the experimental tests for increasing mechanical properties of thick-walled tubes subjected to high interior pressure loads. The theoretical model established a mathematical model of calculus for non-linear environments in the case of self-hooping or autofrettaging of the thick-walled tubes. The mathematical model was validated with experimental tests performed in the Mechanical Engineering Laboratory of the Military Technical Academy in Bucharest on a standard tension test specimens collected from the abutment barrel made out of alloyed steel. Finally, the present paper introduces some theoretical guidelines of hydrostatic procedure in the field of artillery barrels manufacturing, as well as experimental data obtained after using the autofrettage procedure.

scholarly journals A Novel Floating Memristor Emulator with Minimal Components

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Zhijun Li ◽  
Yicheng Zeng ◽  
Minglin Ma
Keyword(s):  
Mathematical Model ◽  
Hysteresis Loops ◽  
Experimental Tests ◽  
Operational Amplifiers ◽  
Current Feedback ◽  
Analog Multipliers ◽  
Current Feedback Operational Amplifiers ◽  
Memristor Emulator ◽  
The Mathematical Model ◽  
Pinched Hysteresis

A new floating emulator for the flux-controlled memristor is introduced in this paper. The proposed emulator circuit is very simple and consists of only two current feedback operational amplifiers (CFOAs), two analog multipliers, three resistors, and two capacitors. The emulator can be configured as an incremental or decremental type memristor by using an additional switch. The mathematical model of the emulator is derived to characterize its behavior. The hysteresis behavior of the emulator is discussed in detail, showing that the pinched hysteresis loops in v-i plane depend not only on the amplitude-to-frequency ratio of the exciting signal but also on the time constant of the emulator circuit itself. Experimental tests are provided to validate the emulator’s workability.

Sign in / Sign up

Export Citation Format

Share Document