Calculating Energy for Water Propulsion with Circular Blades

In summary, calculating the energy required to propel water at 3 metres per second through a circular-type blade would involve determining the mass of the water and its velocity, and then using the equation for kinetic energy. However, this calculation would only give the minimum amount of power required as actual efficiency can vary greatly depending on factors such as the design of the propeller and the Reynolds number.
  • #1
Forlax
1
0
How would you go about calculating the energy required to propel water through a circular-type blade at 3 metres per second??

Thanks.
 
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  • #2
in this case you would be calculating power (energy per time)

think about how much mass is moving, and how fast it is going.

then use the equation for kinetic energy.

bear in mind, that this is the MINIMUM amount of power required, since it is assumes 100% conversion of propeller work to kinetic energy. The actual number is much greater and difficult to predict.

It is probably only estimable by using correlations based on the reynold's number and propeller design.
 
  • #3
Obviously it depends on the device, but you can figure 50-75% efficiency for a pump or propeller.
 

1. How do you calculate the energy required for water propulsion with circular blades?

The energy required for water propulsion with circular blades can be calculated using the equation: E = 0.5 * ρ * A * V3 * Cd, where E is the energy in joules, ρ is the density of water, A is the area of the blades in square meters, V is the velocity of the blades in meters per second, and Cd is the drag coefficient of the blades.

2. What is the importance of calculating energy for water propulsion with circular blades?

Calculating the energy required for water propulsion with circular blades is important because it allows us to determine the amount of power needed to move an object through water using this method. This information can be used to design more efficient propulsion systems and to make informed decisions about the feasibility of using circular blades for water propulsion.

3. How does the density of water affect the energy required for water propulsion?

The density of water plays a significant role in the energy required for water propulsion with circular blades. Since water is more dense than air, it requires more energy to move through it. This means that as the density of water increases, the energy required for propulsion also increases.

4. What is the drag coefficient and how does it impact the energy required for water propulsion?

The drag coefficient is a dimensionless number that represents the resistance an object experiences as it moves through a fluid. In the equation for calculating energy, a higher drag coefficient will result in a higher energy requirement for water propulsion with circular blades. This is because a higher drag coefficient indicates a greater resistance to movement through the water.

5. Are there any other factors that should be considered when calculating energy for water propulsion with circular blades?

Yes, there are other factors that should be taken into account when calculating energy for water propulsion with circular blades. These include the size and shape of the blades, the speed of rotation, and the efficiency of the propulsion system. Additionally, factors such as water temperature, depth, and salinity can also impact the energy required for water propulsion.

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