## Calculations

## Using OWC to Estimate Wave Height

} Wave Pressure: P(z)=-ρgz + ρgKpη

} Assume Shallow Water => Kp = 1

} Assume: Max U occurs at τ/2

} Therefore: ΔP = ρgH, ΔV=H * A0, Δt=τ/2

} Q=H*A0/(τ/2)

} Q= A1*U

}

} Assume Shallow Water => Kp = 1

} Assume: Max U occurs at τ/2

} Therefore: ΔP = ρgH, ΔV=H * A0, Δt=τ/2

} Q=H*A0/(τ/2)

} Q= A1*U

}

**H= A1*U*****(****τ****/2)/A0**## Results

} Measured:

A0= 45.6 cm. sq.

A1=1.27 cm. sq.

τ = 2 sec.

U= 20 cm/s

H=2.54 cm

} Calculated:

H=0.55 cm

A0= 45.6 cm. sq.

A1=1.27 cm. sq.

τ = 2 sec.

U= 20 cm/s

H=2.54 cm

} Calculated:

**H= A1*U*****(****τ****/2)/A0**H=0.55 cm

## Discussion

} Possible Sources of Error

-Shallow Water Assumption: formulas used would have changed

-Strainer Blocking Flow: not a big of pressure difference created as what could have been

-Oscillating Air Flow Interference

-Wave Reflection Interference: Readings desturbed because of the waves refraction on the bathtub walls

-Measurement Error: human error

-Uneven wave generation

-Shallow Water Assumption: formulas used would have changed

-Strainer Blocking Flow: not a big of pressure difference created as what could have been

-Oscillating Air Flow Interference

-Wave Reflection Interference: Readings desturbed because of the waves refraction on the bathtub walls

-Measurement Error: human error

-Uneven wave generation

## Conclusion

Oscillating Water Column is an excellent method for converting wave energy to usable power. Unfortunatly it is not being used yet as a common source of energy.

Using OWC to indirectly measure wave height should only be considered if interfering variables can be kept to a minimum.

Using OWC to indirectly measure wave height should only be considered if interfering variables can be kept to a minimum.

*University of Wisconsin Madison*

CEE 514: Final Project

CEE 514: Final Project

*By: Nicole Johnson & Eric Olson*

Copyright 2010

Copyright 2010