What was once the dream of hippies and Mother Earth News readers is now becoming avant-garde in this time of economic upheaval. With predictions of further woes and the
Likelihood of more and more government regulation of our lives, the thought of living off of the grid (independent of public utilities) becomes more and more appealing to increasing numbers of people.
Wind energy is one of the alternatives generating great interest, as well as solar panels and solar water heating systems. The truth of the matter is, if you purchase hi-tech solar and wind systems for the average home, you will spend so much money that you’ll never recoup your investment, though you may truly be able to live off the grid. In fact, any extra electricity you produce will be purchase from you by local utilities. Still, the cost is prohibitive for the average household.
So many are turning to homemade systems, which may truly be built for a fraction of the cost of a retail investment and offers the same promise of fulfilling the dream of energy independence. A search on the internet will turn up multiple e-books and plans providing just what the would-be builder needs. With these plans you can expect to build solar and/or wind power units for $200 or less. Most of the parts needed may be purchased locally at hardware and auto parts stores.
It is so easy to build these units that any do-it-yourselfer can make them using simple tools and without special skills. There are detailed guides available to show you just how to do it, and they are available by using simple searches on the internet.
About the Author
Marc Hillis
http://www.105westmain.com/diywindturbine.html
New Home Builder VA:How do I choose the best alternative energy
Damping is a phenomenon which exists in every system. Some systems have little and some have more. it is related to what elements and how they are assembled with each other in system .such phenomena dissipate energy and reduce the vibrating caused by external applied forces to system like earth quick, wind ,sea wave and thunder .Different types of dampers have been known regarding to their function: passive, active and semi-active. In the field of passive dampers we have many types: tuned mass damper TMD, tuned liquid damper TLD, friction dampers FD and viscose dampers VD.
The present research experimentally studies damping ratio of a three-storey building using TMD and without TMD damper to see how damper increase the damping ratio . To carry out this study A structure and the necessary equipment including a loading system and a data acquisition system are used.. Structure examined under the free vibration in this way: A small displacement implemented to the structure as a free vibrations. And by carrying out more than 150 tests, the damping ratios of the structure using TMD and without TMD in different loading conditions are obtained. The results show that the Tuned mass damper has a major effect on the damping characteristics of the structure The results also show that the increasing the loading applied to structure doesn’t change the damping ratio which is analyses an Ansys software .
Key Word: damping ,tuned mass damper ,damping ratio
Damping is a phenomenon where the amplitude of vibration in a mechanical system steadily diminishes. The effect of damping is to remove energy from the system. Energy in a vibrating system can be dissipated, being converted into heat [1,2,3].
Damping is present in all vibrating systems. Every system which possesses mass and elasticity is capable of vibration. Dampers are kind of device in order to dissipate vibration forces… Different types of dampers have been known .in general they are divided in three categories: passive, active and semi-active.[4,5,6,7].Tuned liquid dampers[8] and Tuned mass dampers[9] are very usual one which are using nowadays in many structural system and the second one is our research topic.
2 Examined model
In present research A structure is being designed and built as a model of a real structure in Fig.1
Fig 1: drawing and picture of model
the weight of the structure is 200 kg and the stiffness of that is k=6.666 N/mm and the natural frequency is w=0.056 Hz which was analyses in a finite element software Ansys
Fig 2: analysed model in software
3 TMD design [11~25]
in order to design the TMD with study of many books and article and the real TMD used in some real structures in the world like Citicope tower in New York [10] we came to this result : the mass of TMD can consider 2 percent of structure’s mass or less, but it should be design in a optimum way . Natural frequency of TMD Should be as the natural frequency of real structure. When the real structure approach to its natural frequency caused by external applied forces, TMD must approach to its natural frequency too. The vibration of TMD at natural frequency causes turbulence in general movement. In this way the frequency of structure go further from its natural frequency.
As a result, the stiffness of TMD also should consider 2 percent of structure’s stiffness to . be as the same.
The Mass Of TMD: (1)
The Stiffness Of TMD: (2)
After determination of mass and stiffness’ amount of TMD, a block and spring design and then manufactured at Fig 4 and 5.
Fig 4: mass dimension Fig 5: spring dimension
After manufacturing the block as a mass and spring as a stiffness element, they attached to each other Fig 6 and assembled on a bearing Fig.7 in order to have soft movement .
Fig 6. Mass and spring attached Fig 7. Mass assembled on bearing
And finally whole commission on our modeled structure to examine how it effect the damping ratio of structure Fig.8.
Fig 8
4. Method of loading and equipment
To apply load to structure we use a method showed in Fig 9. a block will hang using a rope to structure and suddenly the rope will cut then dropping the block cause a loading which apply to structure .this procedure carry both condition the structure using TMD and without TMD .in this way we have the free vibration condition .
Fig.9
The equipment Fig .10 to record the data is:
a) A sensor which is called transducer
b) A hardware which is called Data Logger which transfer the sensor output to computer
c) A computer and the software of Pulse which show the output in Graph as a graph of time-displacement.
Fig 10
4. Methodology of experiment
in order to have free vibration we should apply the initial speed or initial displacement to the structure. Our method is initial displacement .for this purpose the structure will be loaded bye some block and by make them free from the structure the initial displacement will apply to structure .the loading carried out using steel block and different size fro 15 kg until 75 kg with the step of 10 kg. The test carried out nearly 150 times to get to a correct conclusion.
5. Getting Data [26]
Using experiment equipment we come to a time-displacement graph which is being showed in Fig 11 , 12 .the first graph shows the displacement of structure under the free vibration using TMD and the second one not using TMD.
Fig 11.Time –Displacement Graph for system without TMD
Fig 12. Time _Displacement Graph for system with TMD
It is clear if we confess on both graphs it shows the Maximum Displacement reduce from 1.3 mm to 1.1 mm.
For all the graph we use the ‘logarithmic decrement’ method to calculate damping ratio . Fig 13 shows a graphical representation of a damped free vibration. The motion shown in Fig 13 may be represented by the equation:
(3)
Where
Is the natural frequency, is the damping ratio of the system and X and are arbitrary constants determined from initial conditions.
The natural logarithm of the ratio of any two successive amplitudes, for example and in Fig 1, can be written as:
(4)
Where and can be obtained from Eqn 3 at t=t1 and t=t2=t1+τ, respectively. Inserting these values of and in Eqn 4 will result in the following equation:
(5)
For every step of loading we get the result showed in table1.
Table 1
6. Results
- Damping ratios change with applying different loads for the system not using TMD instead it will not change for system using TMD .thus it can be show that using Tmd increase the damping ratio but if the amplitude of system increase cause by Appling more forces, it will not change. . A Tuned Mass Damper has constant behavior.
- For optimize performance of TMD it is better to design optimum range of 0 to 2% of mass and stiffness of real structure
. If we suppose the structure like a cantilever beam, the edge of the beam has more displacement during vibration, so it is rational to locate damper where there is more displacement.
Reference
1- Jeary, A. P., and Ellis, B. R., ‘Vibration Tests on Structures at Varied Amplitudes’ proc. ASCE/EMD Specially conference on Dynamic Response of Structures, ASCE, Atlanta, GA, 1981
2- Barkanov, E., ‘Transient response analysis of structures made from viscoelastic materials’ International J. for numerical methods in engineering, vol. 44, 1999
3- Allen, D. ‘The Mero Space Frame System’ Proceeding of Australian Conference on Space Structures, Melbourne, Australia, 1982.
4- Samali B, Kwok KCS. Vibration control systems for civil engineering structures in Australia — actual installations and state-ofthe- art research. In: Proc. 2nd Int. Conf. on Motion and Vibration Control, Yokohama, Japan, 1994:k22–35.
5- Tamura Y. Suppression of wind-induced vibrations of buildings.J Wind Engng, (JAWE), 1990;44:71–84.
6- Kareem A. Mitigation of wind induced motion of tall buildings.J Wind Engng and Industr Aerodyn 1983;11:273–84
7- Structural control by induced stress based stiffness modification by By Katie Patricia Whipp ,Augest 2005 nashaville Tennessee .
8- McNamara RJ. Tuned mass dampers for buildings. J Struct Engng, ASCE 1977;103(ST9):1785–98.
9- Fujino Y, Sun L, Pacheco BM, Chaiseri P. Tuned liquid damper (TLD) for suppressing horizontal motion of structures. J Engng Mech, ASCE 1992;118(10):2017–30.
10- USGS Response to an Urban Earthquake Northridge 94, Prepared by the U.s. Geological Survey 1 for the Federal Emergency Management Agency (FEMA) Open-File Report 96-263, 1996.
11- Den Hartog, J.P., 1956. ”Mechanical Vibrations, ath Edition”. McGraw-Hill. New York, 436 PP.
12- Frahm, H., 1909. ”Device for Damping Vibration of Bodies” , US Patent No. 989958, Oct. 30, 1909.
13- Anderson, B. D. O., and Moore, J. B. (1990). Optimal Control: Linear Quadratic Methods, Prentice Hall, Upper Saddle River. N.J.
14- Bachman, H., and Ammann, W. (1987). Vibrations in Structures, IABSE, Zurich.
16- Brogan, W. L. (1991). Modern Control Theory, 3rd ed., Prentice Hall, Upper Saddle River, N.J.
17- Chopra, A. (1995). Dynamics of Structures, Prentice Hall, Upper Saddle River, N. J.
18- Clough, J. W., and Penzien, J (1993). Dynamics of Structures, 2nd ed., McGraw-Hill, New York.
19- Soong.T.T., and Dargush, G. F. (1997). Passive Energy Dissipation Systems in Structural Engineering. John Wiley & Sons, New York.
20- Strang. G. (1993). Introduction to Linear Algebra, Wellesley-Cambridge Press, Wellesley, Massachusetts.
21- Suh. N. P. (1990). The Principles of Design, Oxford University Press, London.
22- First World Conference on Structural Control (1994). Intemational Association for Structural Control, Pasadena, California.
23- 11th International Conference on Structural Mechanics Reactor Technology (1991). Seismic Isolation and Response Control for Nuclear and Non-Nuclear Structures, Tokyo, Japan.
24- International Workshop on Recent Developmenis In Base Isolation Techniques for Buildings (1992). Architectural Institute of Japan. Tokyo, Japan.
25- Mechanical Eng. Design by Shigley, Shigley, Sixth Edition
26- Thomson, W.t., “Theory of Vibration With Application” 2nd Edition, London, George Allen & Unwin, 1993.
About the Author
hadi sheydaie master of science mechanical engineer mazandaran university iran
Green-Trust.Org & Woodhenge.Org building wind turbines
what field should i look to go into when i get to college?
im really good at and love math and science, my dad was first an engineer so that is sort of an option, but i am especially interested in alternative energy, solar power, and that sort of field dealing with current environmental problems….what kind of majors are out there for this type of work? i just have no clue at this point where i want to go in terms of study, there are so many choices and neat fields out there, medicine is also an option, nanotechnology and biochem and that sort of stuff also interests me, but i dont know enough about any fields to choose yet….
i guess my question is what kind of field would best suit me and also have the most potential for $$$, as that is what this all amounts to in the end….
If you are interested in alternative energy, try looking into Earth and Environmental Engineering or even Civil Engineering.
If you are interested in medicine you could do Biomedical Engineering or Electrical Engineering.
If you need more help, do not hesitate to e-mail me!
Indosolar signs deal with Chinese solar energy company
Market for Wind Energy: Turbine Components & sub-components and demand in the us and the world reports
Company in the manufacture and sale of Related products involved the production of wind energy are expecting a banner year for 2009 as a new customer base Inherit the Wind as their primary energy source. But some manufacturers with an eye to expanding its market presence in the U.S. were waiting with bated breath. By early 2009, the U.S. president Barack Obama will have opened, who are consumed with the healing of the nation from an economy in ruins. His actions could have a domino effect on the spending intentions of businesses and consumers who Reflect the change to renewable energy sources as a means to lower energy and the promotion of environmental technology, have reduced greenhouse gas emissions. Obama said he would invest in renewable energies 15000000000 $ per year to five million new jobs in energy by 2018. He also said he would emphasize, to spend a program of 150 billion U.S. dollars over 10 years to develop renewable energy sources such as wind, and to promote energy conservation.
SBI estimates the total cost of wind energy market in the U.S. is estimated at 151.3 billion U.S. dollars. The U.S. wind industry expanded rapidly in 2008, fueled by three key drivers of the market:
Skyrocketing fossil fuels and the price of oil for industrial and domestic heating
Long-term demand for renewable energy sources in Germany
Improvements in technology, the manufacture of wind turbine power lines, especially in larger machines required for offshore wind farm initiatives
Positive employment outlook in the turbine manufacturing industry
Scope and Methodology
This Report includes both primary and secondary research. Secondary research data from government sources, trade association publications has been obtained, magazines and literature Company. Statistical data for the industry revenue, both globally and recorded for the United States. Historical data are provided for 2002-2008 Time-frame with projections of future revenues by 2013. The base year for the report, 2008.
The report covers shipments, imports and exports and economic and market trends driving the wind industry. There are important market trends and dynamics, and profiles major market players, in which they maximize their strategies for growth and profitability.
SBI's research methodology for this report involved aggregating, synthesis and analysis of data from multiple sources, including the U.S. government and several third-party market research syndicated data suppliers. Historical data on the manufacture and sale of wind turbines in the U.S. are products of the U.S. Department of Commerce, the U.S. Census Bureau, culled and the Bureau of Labor Statistics. The analysis of these data, including market-level shipments, imports and exports are the basis for our projections of overall market Size and growth over the next five years. Our projections also take into account data that indirectly affects the growth of wind power market, such as information by the U.S. Department of Energy, National Renewable Energy Laboratory service account, and the American Wind Energy Association.
The total value was used show the market supply of wind energy products, develop products specifically manufactured wind turbines. Shipping statistics from the U.S. Census of Manufacturers and the Annual Survey of Manufacturers derived and estimated and projected by SBI.
How will you Benefit from this Report
This Report is a "must read" for manufacturers of wind turbines and associated components such as gears, meters, towers, nacelles and blades. These companies understand the current market size of wind turbines worldwide and the U.S. position among other nations. The report examines the countries with the largest Opportunities for domestic wind energy development and looks at the growth potential for manufacturers of large and small turbines for the consumer market. Manufacturers can be found The report provides a thorough analysis of wind energy production and how companies their products to compete with other popular sources of energy.
This report will help:
Marketing managers identify market opportunities and develop plans for the Development of Wind Energy Products
Research and development professionals keep up competitor initiatives and product innovations
Advertising and public relations agencies working with clients in the wind energy industry to create targeted and compelling messages about the benefits of wind energy products
to identify business development manager for wind energy companies, potential Partnerships and explore new product applications.
I often see cars with environmental magnet to them that I could not figure out where to buy. only I saw two. One is round, green, and says "Support Wind Energy", and it is the same as Jesus was in the lower part of noblepower.com. Others another is green and square, and says Yes wind energy, with Y as a windmill. Anyone know where to buy them? I've checked ebay with no luck: (
Contact the company, tell 'em you want to give them some free advertising, and stand back.
How To Build A VAWT Vertical Axis Wind Turbine Arthur Illinois
