Presentation on theme: "Jenny Novak. A technique used to generate small droplet size Used two different ways, one is where you pour water over the ultrasonic transducer, the."— Presentation transcript:
A technique used to generate small droplet size Used two different ways, one is where you pour water over the ultrasonic transducer, the second is you vibrate a tube to create the droplet size http://www.youtube.com/watch?v=CwGAfgs4w ds&feature=related http://www.youtube.com/watch?v=USo8ZoMD Mfk
Medical Field (vapor inhalation) Commercial Humidifiers Fog machine Agricultural equipment?? Ultrasonic Nebulizer (Used for administering medication)
Waves that have a boundary between two fluids. In this case its air and water. Dynamics are mainly due to surface tension. (Like the string, when it has a high tension we see a higher frequency, with lower tension, lower frequency.)
The sound waves from the transducer excite the water waves until small droplets break off
This relates wave frequency to wave propagation speed. ( λ =v/f) k= 2 π / λ ω = angular frequency (2pi*f) σ = surface tension coefficient ρ = density of the heavier fluid ρ = density of the lighter fluid *my experiments will only contain one fluid so I can get rid of ρ
From Rayleighs The Theory of Sound We start with assuming the forces are conservative and use Newtons laws, and obtain equations of motion. From the fact that there is no flux in or out we can use Gauss Divergence equation and show that the velocity potential is equal to zero. Want the velocity potential equal to zero so we can solve for the velocity, and relate it to frequency. Bring in a pressure equation, which is where we can bring the tension and density into the equation.
Uses sound waves to produce droplets Dispersion relation is how we can get the wave frequency to wave propagation speed From the dispersion relation we can obtain Rayleighs equation, Kelvins equation and Langs relation which relates droplet diameter to frequency.