Abstract— A statistical study continues to be conducted specifically graphical evaluation to investigate breeze flow above roof of the constructed composition of various designs from aspect views like the conventional composition, fillet, dome shaped, fifty percent wedges. The speed contours and velocity users have been the points of declaration to find out the form having the efficacy to initiate the turbine rotation. In addition , the suitable site for increasing wind turbines have been illustrated and the desired roofing shapes for future properties are recommended to be built in Bangladesh. Computational end result shows that dome shaped roof structure delivers the utmost velocity of most the additional shapes taken into consideration here. However, when sides are filleted the velocity includes a relative increase than the regular one. Example shows that among all the urban centers Chittagong, Comilla and some selected places in Dhaka have the minimal wind speed to initiate the turbine to build energy.
Keywords— Wind Turbine, Energy, Fillet, Wedge, Dome, Velocity users
Bangladesh is a growing country in South Asia. Dhaka is a capital and largest town, followed by Chittagong. Bangladesh may be the world’s eighth most populous country. The speed of population here is growing day by day. Also, there is deficiency of accommodations and also lack of lands. Therefore , a large number of buildings without any proper design and style are built in an unplanned manner. Regardless of this unavoidable condition these buildings can be utilized as the source of power technology. The power produced in our country is not sufficient to protect all the areas. In addition , the pollution is growing sharply with all the increase of industrial advancement. This requires to reduce environmentally friendly impact whenever possible. Demand is usually higher than the production. To meet the demand, building-integrated micro-wind generators are recommended to install on the roof of commercial along with residence buildings to generate energy. Wind turbine power of a wind generator  can be expressed as follows:
Where, may be the wind turbine power, is the air flow density, is a co-efficient of performance, A is the hidden area of the rotor blades and V is totally free wind velocity (m/s). To sum up equation, it is showed that the power of wind increases while using cube from the wind rate.
Alternatively, the rate of carbon release is rising day by day. A great expansion inside the degree of open public awareness about the effect of Garden greenhouse Effect on the nature and the damaging effect of our dependency in fossil fuels provides acquired a developing excitement on site-generated electricity via sustainable powers. Therefore , utilization of fossil fuels must be reduced to minimize environmental harm. Hence, major is upon alternative strength solutions, that may reduce each of our carbon footprints.
The Global Institute of Sustainability building located in Illinois State University or college has mounted 6 wind generators and under average condition, 36 computer systems can manage with the produced electricity. The wind turbines let in there will produce electricity with winds to 5 with . Numerous research regarding using urban wind flow energy have been done beforehand and a few provides given tips of additional work.
Durson (2012) has introduced the concept of Building Increased Wind Turbines (BAWT). The advantages of roof mounted wind turbine was represented by him. The concept was to make use of the buildings since an gas of breeze . Study of Islam Abohela (2013) demonstrates that as house height boosts, the wind velocity increases and accordingly the yield of a roof installed wind turbine raises. He also available, barrel-vaulted roofing is the desired roof form for increasing wind turbines on the top in order to increase wind above the roof . In another study of Islam  different designed roofs had been compared and stated that mounting wind turbines on barrel or clip vaulted roof would deliver 56% more electricity when compared to a free ranking wind turbine at the same location. Even though wedge designed roof can deliver just 9% even more electricity when compared to a free ranking wind turbine, it really is more feasible to take the advantages of the building’s acceleration impact . On the other hand, Sari (2012) located through statistical analysis and wind canal test the fact that wind rate raises in the middle of rounder towers . Intended for the details setup in wind flow simulations, S i9000. Murakami (1993) have reviewed the variations of disturbance models and finished plan a decision that no style can simulate wind movement over buildings splendidly, although standard turbulence is a standout amongst the best models and is broadly utilized .
EXAMPLE ON WIND FLOW
An instance study is very important to identify appropriate locations to mount wind turbines where maximum efficiency work extremely well. Nandi (2012), in his study uncovers that Kutubdia and Kuakata have potential for wind power. His result demonstrates that the average wind flow speed is approximately 4. 17 m/s . The residential areas where the alignment of the complexes is similar and gap between buildings happen to be standard are eclectic intended for the construction of wind turbines. Besides, the environment should be such that below average condition, the wind acceleration is at least 3-4 meters per second (m/s). Many wind turbines commence generating electrical power at wind speeds of around three to four m/s (8 miles per hour) . Bangladesh Meteorological Division has done stats on distinct places month-to-month and offered annual outcomes on that basis . Statistics show, on the month of Summer and September, Chittagong provides the highest wind flow speed of around eight. 7 m/s. On the other hand, Jessore possesses wind speed of 6 m/s on 04 and May. Likewise, Cox’s Transaction has a comparatively higher wind speed about June and July. Dhaka, Sayedpur and Comilla have a similar kind of wind speed on April, May, June and July which can be around 4m/s. The annual wind speed of four distinct months in those urban centers of Bangladesh is charted below:
The idea the following is to see the chance of this plan through computational approach to see how wind speed can be put to rewarding use to find the desired electricity generated via wind turbines. Furthermore, different roof top patterns are looked into in statistical approach to find out a suitable one for foreseeable future construction. The side views of the future structures are noticed in computational methods individually. Aspect views include normal framework, fillet, dome shaped and half sand wedge. From the numerical results the possible combinations are seen.
COMPUTATIONAL SETUP DATA ACQUISITION
In accordance to Bangladesh National Building Code (BNBC) , A 10 varied building needs to be at least 32 metres in height [e. g. h=32 meter]. According to the proportion, width was handed to be 21 years old meters [e. g. w=21 meter]. This is accepted as the research for computational domain dimensions. The domain name is 5. 57w in length and 1 ) 52w high. Line of the roof is taken as the datum line. The rooftop is targeted in these research and parts lower in the ground are not included as the mounting of wind turbines happen to be suggested intended for rooftop.
The website consists of triangular in shape elements and number of factors are around 9000. Dhaka, Chittagong and Cox’s bazar a new velocity of 4. 21 years old, 8. 77 and 6th. 15 m/s respectively in certain selected weeks. Most of the velocity fluctuates between 4 and 8 in various cities. Consequently, the former was taken as input to find out the results. The temperature is defined as 303 k. Computations are executed in realizable k-ε unit as it contains a altered transport equation for the dissipation price. Also the[desktop] is useful for and validated intended for boundary coating flows. The numerical effects obtained specially the Velocity curves and Speed profiles over the building for different altitudes were the problems of declaration.
Each of the aforementioned designs were 21 years old meters long. As the rooftop is definitely taken as recommended location to put in the generators the complete elevation of the tower was not considered. In addition , the wind velocity near to the ground certainly will not be good enough provided that the vast inhabitants as well as densely constructed structures. The wind velocity taken as input was four. 21 m/s which is greatest for Dhaka recorded inside the chart provided earlier. Just for this specified type computations were done for all of the aforementioned forms. There were some wakes produced behind the typical structure. However , when the sides were fillet it had a rise in velocity compared to the conventional one. In the standard one optimum velocity was 4. fifty four m/s although the latter a single had a maximum velocity of 6. 51 m/s, enough to start the rotation of the generator blades. The fillet framework had this kind of maximum benefit near the 4 corners. Furthermore, dome shaped framework which a new radius of 12 yards was noticed to have the greatest of velocity among all several. The maximum speed which happens at the for 10 million baht in thailand (divide that by three for the rest of the developed world). the top from the dome is 7. 42 m/s. The wedge was given an position of 10o and had a low increment of velocity.
RESULT ANALYSIS AND ASSESSMENT
The velocity profiles were plotted at different l/w percentages. Where m is the height from datensatz (fachsprachlich) line and w is a width in the building.
The computational domain stretches upto 96 meters the place that the building width is coming from 35 to 56 meters. The velocity information particularly targets that section of the solution. At four different l/w percentages the users are drawn below.
The velocity users shown over are intended for four distinct ratios as well as the lines happen to be along the datum level. It truly is observed from your figure that the dome formed roof come to the highest velocity at distinct ratios. Although the fillet has comparatively improved account than the conventional one. For l/w = 0. 16 the dome shaped has a velocity above 6 m/s. The conventional speculate if this trade a relatively frequent velocity over the datum level whereas the filleted rooftops have a small increase in velocity. Wedge shaped rooftops a new relatively low initial speed at the contact level of initially edge. Though it had a steeper slope compared to conventional as well as the filleted 1 the maximum speed reached by this 10 degree half wedge shape has not been above than that of individuals. As a whole all the curves at different percentages maintain the same pattern.
The four forms that were investigated here are proposed as the side views of the structures to get future properties. The effects suggest that dome shape must be preferred for maximum usage of turbines. Yet , when the corners are filleted the causing velocity boosts a lot better than the typical structures. A slight amount of increment in velocity will mean a higher sum of electricity generation. Pitching wedge having a 12 degree would not have an powerful increment in velocity to make a desired impact for green application. Even more studies can be conducted by varying the wedge angle as well as the radius of the dome shaped structure.
Yet , there are some restrictions which has to be considered. Wind speed through Bangladesh is usually not the same through the years. The a few months with relatively higher velocities are charted earlier. The Turbine variety is of extremely important importance since the sound and sto� levels come into account. Encraft Windcrift Breeze Trials Project (2009) and Wineur Job (2007) claim that the brake disc of the wind turbine must be mounted at least 30% over a building height from the toned roof level. However , there is advancement in technology in turbines and it is suggested here that parapet wind turbines are the solution on this problem. Illinois State School used this sort of turbines. It is just 6. 5 feet taller and weight around sixty pounds. It may produce electrical power even by 5mph wind flow speed. The availability rate is usually 55kWh each month. Moreover, that reduces tones as well as sto� which is also main concern.
In addition , temperature and blowing wind speed are dependent parameters on each other. The study done here a new constant temperatures although the practical scenario could differ. Also, a great experimental research is necessary for even more evaluation of real life applications. The cost analysis as well as the power generation should be investigated. The wind velocity will probably be nonuniform in various locations which in turn also comes into account. Sometimes it is even challenging to get blowing wind speed of 5mph in Bangladesh specially in Dhaka. New types of generators are in progression intended for increased efficiency to spin the turbines at wind flow speed low as 4mph (2m/s).
The vision 2041 of “Digital Bangladesh” is to accept the whole region under the adnger zone of renewable energy for the presevement of Green Environment. Utilizing the wind flow to build energy is a promising prospective client to mitigate the usage of non-renewable fuels and ensure a pollution cost-free environment later on.