Tuesday, June 29, 2010

3. Evaluate

a. ) Performance at Each Stage
Investigate
Here, I made a positive contribution to the research of the group, and everyone played their part well. The only improvement here is that we should have researched and found out the availability of tools in the DT lab, before starting to design our product, as later on we did not have access to a soldering iron.

Design
The designs our group made were all quite well-thought-out, and choosing one took a while. The only drawback here was that, even though the group collaborated with ideas on how the designs should be, only one member of our group knew how to use Google Sketch-up effectively, and we could improve by all learning how to use Google Sketch-up

Plan
Here, we could have improved, as our plan was too rigid, and did not allow space to multi-task and was more like a plan for one person than 3. This could be improved on. Also, we did not account for the unavailability of a soldering iron, and we should have had a backup included into our plan.

Create
Here is when our group realized that the originally intended product would not turn out the way it was meant to, and found alternatives to the places where we were not meeting our expectations. This was partly due to unavailability of materials (soldering iron), and impracticality of some of our ideas (V-bottom hull, motor). We could improve here by adding these modifications to the plan as we went on.

Attitudes
Over the course of this project I have contributed well to my group’s activities and taken a role in making decisions and choices regarding the product. Sometimes I did get sidetracked, seeing as the machines were constantly in use, and there was a shortage of work to be done. Even though I did effectively complete the project eventually, I should minimize distractions. Another improvement could be learning how to use Google Sketch-up.

b.) Success of Product
The product that I created was quite successful in some ways, and unsuccessful in others. The marine vessel itself was a success, as it stably floated on water with minimal rockiness, and was also stable at speed, just as intended. The only drawback about it was that there was a lot of water building up in the front as the V-tip cut through it. This could be improved on. The initial idea was to create a motor-powered, V-hulled boat, and we were unsuccessful there, as our boat was flat-bottomed and human-powered. However, even with the shortcoming there this marine vessel does solve the problem we intended to. Now that it is longer, it can be used to test the efficiency of freight carriers. It still solves the problem we identified, which was to save money on designing and testing real-life marine vessels, which is very expensive to do in real life. So, since the problem has been solved by us enabling the small-scale testing of freighters, it is successful.

Monday, June 28, 2010

2. Influence of Hull Design, Material and Propulsion

The choice of hull design in our boat was influenced by the research we conducted and our own experience personally. First, from our research, we realized that the V-hull was the best idea, as we found out that it provided a smooth ride, and were designed to operate at high speeds. The choice of propulsion method was also influenced by the hull design, as we found out that V-hulls needed higher power to operate properly, so we decided to use an onboard motor which would power a propeller through the use of a shaft. The material was also influenced by this, as we thought that we would use acrylic and seal it by melting the edges. However, once we tried to apply this practically, it all changed. After a few weeks we realized that:
1. It would be very hard to find and assemble a motor and propeller system.
2. The V-hull would also be very hard to balance the weight.
3. The soldering iron was not available.

So, we decided to:
1. Use human propulsion to power the boat.
2. Make a flat-bottomed boat with a pointed tip.
3. Use sealant to fix the edges of the boat.

1. Different Types of Marine Vessels

Flat-Bottomed
Flat bottom boats are usually small open boats such as john-boats. Flat bottomed boats can easily ride on top of the water at high speeds. Flat bottom boats are typically used on calm waters such as small lakes and slow rivers because they do not handle well in choppy water, especially at very high speeds. Flat bottomed boats are not very stable, however, as they move with the flow of the water.











 Deep-V-Hull
V-hulls are designed to operate at high speeds and to "cut" through rough water, which provides a smoother ride than flat-bottomed or round hull boats. V-hulls are not as efficient as flat or round bottomed boats, and need larger engines to move at similar speeds. Most of the boats sold today are V-hulled in one way or another. However, they may tip over sideways under high side-winds.



 







 Round Bottom Hull

Round bottom boats almost "glide" through the water. Most cruising sail and power boats have rounded hulls because they are efficient at moving through water. Typically, round hulled boats move at slow speeds.


  
 






 Cathedral Hull

Cathedral or multi-hulls, are two or more hulls attached closely together. This combination of hulls makes sure there is much more stability than what is found in other hulls.The air between the two hulls can provide lift and make sure there is less drag on the boat from the water. However, the extra air resistance may flip the boat over if it is too light. 


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