# Water vortex

1. Apr 2, 2012

### hao1030

can anyone tell me how the orifice diameter can affect the vortex forming ?
no much info from internet , thx for help~

2. Apr 2, 2012

### Bobbywhy

hao1030, Welcome to Physics Forums!

Are you asking about a "bathtub" vortex? What orfice are you referring to? Will you please describe your experimental setup in more detail? This will help all the members here to respond more effectively.

Thank you, Bobbywhy

3. Apr 2, 2012

### hao1030

it is water vortex power plant
http://en.wikipedia.org/wiki/Gravitation_water_vortex_power_plant
i have a basin with a certain orifice diameter , i want to know how this orifice can influence my vortex forming and it height/ strength .

4. Apr 2, 2012

### 256bits

Last edited by a moderator: May 5, 2017
5. Apr 2, 2012

### Bobbywhy

Hope this helps! Here find a pdf document with the mathematical formula for controlling the outflow (which appears to be applicable from a water vortex) by varying the cross sectional area of the opening:

618 WSUD09: CONFERENCE PROCEEDINGS
TOWARDS WATER SENSITIVE CITIES AND CITIZENS: THE 6TH INTERNATIONAL WATER SENSITIVE URBAN DESIGN CONFERENCE AND HYDROPOLIS #3

Flow Controls
Conventional flow control devices such as orifice plates, throttle pipes and penstocks have traditionally been used for controlling outflows from retention and detention structures. The fundamental equation governing the operating characteristics of most flow control devices is given by equation 1: The formula shows that in order to reduce flow rate (Q) for a given operating head (h), you either need to reduce the cross sectional area (A) of the outlet or the co-efficient of discharge (Cd) for the flow control device. Orifice plates have a fixed co-efficient of discharge (typically ~ 0.6) which means that smaller aperture sizes are needed to reduce flow rates.

Where Q = Continuation flow in m3/s
Cd = Coefficient of discharge
A = Cross-sectional area of outlet (m2)
g = Acceleration due to gravity (m/s2)
h = Differential head across flow control (m)
Q = Cd A 2 gh

www.rocla.com.au/Drawings/WSUD%2009_Vortex%20Flow%20 [Broken]...

Last edited by a moderator: May 5, 2017
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