Wind Turbine Engineering Challenge. By g Roup

Transcription

1 Wind Turbine Engineering Challenge By g Roup

2 Construction Questions

3 Obstacles Our two most significant obstacles were with the blades not fitting into the hub and with our blades not being properly attached to the dowel rods. First, when we tried to get our dowel rods into the hub, the rods were too thin and were slipping out. We decided to fix this by taping the connecting part with duct tape until it fit properly. After that, we found that our blades not properly being attached to the dowel rods because we attached them using just duct tape. This proved ineffective, since the blades were wobbling, so we secured them down with hot glue and then added the duct tape over it.

4 Materials We used cardboard for the blades and then covered the curved edges and the sides to the right of them in masking tape to smoothen the uneven edges. Dowel rods were used to connect the blades to our hub and attached to the blades themselves with hot glue along the rods and covered with duct tape. We then used more duct tape as well as sellotape to make the dowel rods fit into the hub, which was an effective solution.

5 Determining Blade Design Using computer programs to test blade designs, we found that the design that worked best was a thin and long blade, but at the same time not so thin that they were sensitive to movement or cover more area than what the fan s wind would reach.

6 Determining Blade Number We determined that 3 blades would work best for us by referring to the construction of large-scale modern wind turbines. In the end, we modeled ours after these to reach maximum efficiency because we figured that the modern wind turbines produce a lot of power but without the stress that comes with additional blades.

7 Blade Length We wanted our blades to be long, yet still not longer than what our fan would cover when turned on. In the end we decided that a length of 35 centimeters was a good compromise that adhered to all of our requirements (for lack of better word).

8 Blade Pitch (Angle) We didn t want to have our angles too sharp, yet we needed them to be sharper than they were originally, without modifications, so we angled them slightly at ten degrees.

9 Issues With Friction Our biggest issue with friction was that the dowel rod had at first created so much friction in the hub that it was very difficult to adjust, especially when trying to alter the angle of the blades.

10 Blade Balancing One of our most significant issues was with balancing our blades, for at first our blades would wobble when our hub spun. We conquered this by securing our blades to the dowel rods with hot glue and thickening the ends of the dowel rods to more securely attach the blades to the hub.

11 Our Most Effective Changes Securing down the blades and changing the pitch were our two most effective changes. Like we said in the obstacles section, our blades were barely moving and our wind turbine was overall not working well. As a solution to this problem, we added hot glue along with the duct tape to make sure they wouldn t move, which resulted in a great increase of efficiency. Along with that, when our blades were in line with the hub (or flat, for lack of better word), there was hardly any spinning, but with a small change in pitch, they spun a lot better.

12 Concept Questions

13 Environmental Benefits, Tradeoffs, and Challenges of Using Wind for Electricity The biggest environmental benefit of generating electricity through wind turbines is that it reduces coal emissions greatly. Fossil fuels, another form of electricity, emits carbon dioxide and hurts the environment which doesn t happen in wind turbines. The two negatives are that it isn t as effective and more expensive than fossil fuels. As we know, the turbine can only be 59.3% efficient according to Betz Limit, which is not very effective. According to windustry.org, it can cost anywhere from 1-4 million dollars to build one, and when you imagine a whole FIELD of them, the numbers add up quickly. A big challenge in making 20-30% of our energy wind energy is that wind is not reliable, and so sometimes the amount of energy being produced would be inconsistent.

14 Sources of Energy in the U.S. According to the U.S. Energy Information Administration, about 65% of the 4.08 trillion kwh of electricity generated in U.S. facilities in 2016 was from fossil fuels such as coal, natural gas, and petroleum. Natural gas generated 33.8% of that 4.08 trillion, making it the U.S. s primary source of electricity. In Kentucky, our energy comes mainly from coal, which comprises 94% of the energy we produce (2008). Crude oil, natural gas, and renewable energy resources made up the remaining 6%. In 2016, 5.6% of the U.S. s electricity was generated by wind, and as of 2017 we have more than 82 GW of wind power capacity.

15 Wind Energy in the U.S. Wind is caused by differences in atmospheric pressure. The windiest part of the U.S. is Omaha, Nebraska, but most of the turbines are located in Texas, along with Iowa, Oklahoma, California, and Kansas. The U.S. also uses offshore wind turbines in places like Rhode Island, because there are better winds offshore which in turn causes the turbine to produce more power.

16 Why Can t a Wind Turbine be 100% Efficient? It can t be 100% efficient because some of the energy is lost in heat and sound energy that is produced, the maximum efficiency of a turbine is also known as Betz Limit. is this slide finished?? i m too lazy to read it

17 How do we make it more efficient? We can make it more efficient by using lighter material for the blades and adding more blades, as having a lighter material would decrease the stress of the additional blades on the turbine. The problem, however, with this plan would be that it may not be sturdy enough to handle high speed winds, so a compromise would need to be made. To make the turbine more reliable we could add in that and modify it so that it store energy more efficiently for the days that are not as windy as others.

18 Resources energy.ky.gov/documents/kentucky%20energy%20profile,% pdf