Title: Using a Wave Tank to Investigate The Effects Of Different Water Depths On the Height Of Waves

Question: How will wave height respond to changes in water depth?

Materials:

1. A 7ft by 3.5ft wave tank “See Building Method document”
2. Ruler
3. ipad and GoPro for filming

Methods:

1. Wait for the water in the tank to be completely still before the first test
2. Start the video
3. Push the wave generator forward to create swell
4. Watch the slow motion video  and see how high the water reached on the ruler
5. Record the wave height and observations
6. Repeat this for the remaining tests for the different plunge depths

Hypothesis: If the water is 5cm deep then the wave will be 1cm tall

If the water is 7.5cm deep than the wave will be 3cm tall

If the water is 10cm deep the wave will be 5cm tall

If the water is 12.5cm deep the wave will be 7cm tall

If the water is 15cm deep the wave will be 9cm tall

Overall, if the water depth increases then the wave height will increase.


Discussion:

      The goal of our project is to make a scaled down version of a perfect wave and to test the size of our wave in different water depths. A perfect wave must have perfect shape. In most surfers eyes perfect shape for a wave is one that peels and barrels. This means that the wave is following the reef, sandbar, or point and breaks over for a long time. The barrel of the wave is when the wave is making a tube that a surfer can ride inside of. We have learned that usually a larger change from deep to shallow in the sandbar or reef means a more hollow or barreling wave. Overall, we are building our wave tank to find the impact water depth on wave height. 
   
      In words this is what happened, we tested five water levels in our wave tank to see how they would impact wave height. We tested depths of 5cm, 7.5cm, 10cm, 12.5cm, 15cm. Our hypotheses were close but we overestimated a little on each water level. For the 5cm water level we predicted that the wave would be 1cm, it was actually 0cm because although water serged the wave never broke. For the 7.5cm water level we predicted the wave would be 3cm high but it averaged 2.17cm tall. For the 10cm water level we predicted that the wave would be 5cm, it only averaged 3.5 cm. For the 12.5cm water level we predicted the wave would be 7cm tall but it averaged 4.67cm. So because of these results we can see that although our hypotheses were a little larger than our results they were pretty close for an educated guess. 

      Some potential sources of error that could have occurred when testing could have been not filing the tank to the exact level that we were testing. This could have happened when turning off the hose and that could have resulted in a little too much or too little. This could have affected our data by a tiny bit but it still had an effect. Another flaw in our data could have happened when creating the wave. We manually pushed the wave generator and this could have resulted minor inconsistencies in the wave height. In the future I would use a consistent and reliable metal arm that pushes the water and makes the wave every time. I would also try to be more exact with filling it by pulling the hose out and always have someone watching the tank as it fills.


Conclusion:


Overall, we concluded that for waves in wave pools the deeper the water the wave is breaking in the larger the wave.

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