Water Hammer Maximum Surge Pressure Head

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Water Hammer Maximum Surge Pressure Head Formula

\(\large{  h_{spf}  =  \frac { \alpha \; \Delta v   }   { g  }   }\)  (maximum surge pressure head)
\(\large{  p_{spf}  =  \frac { \alpha \; \Delta v \; \gamma_f  }   { 144\; g  }  }\)  (maximum surge pressure for a fluid)
\(\large{  p_{spw}  =  \frac { \alpha\;  \Delta v   }   { 2.31\;g  }  }\)  (maximum surge pressure for a water)

Where:

 Units English Metric
\(\large{ p_{spf} }\) = maximum surge pressure for fluid \(\large{\frac{lbf}{in^2}}\) \(\large{Pa}\)
\(\large{ p_{spw} }\) = maximum surge pressure for water \(\large{\frac{lbf}{in^2}}\) \(\large{Pa}\)
\(\large{ h_{spf} }\) = maximum surge pressure head \(\large{\frac{lbf}{in^2}}\) \(\large{Pa}\)
\(\large{ \Delta v }\) = fluid velocity change \(\large{\frac{ft}{sec}}\) \(\large{\frac{m}{s}}\)
\(\large{ g }\) = gravitational acceleration \(\large{\frac{ft}{sec^2}}\) \(\large{\frac{m}{s^2}}\)
\(\large{ \alpha }\)  (Greek symbol alpha) = pressure wave velocity \(\large{\frac{ft}{sec}}\) \(\large{\frac{m}{s}}\)
\(\large{  \gamma_f } \)  (Greek symbol gamma) = unit weight of fluid \(\large{\frac{lbm}{ft^3}}\) \(\large{\frac{N}{m^3}}\)

Solve For:

\(\large{ g =  \frac{ \alpha \; \Delta v }{ p_{spf} }   }\)  
\(\large{ \Delta v =  \frac{ p_{spf} \; g }{ \alpha }   }\)  
\(\large{ \alpha =  \frac{ p_{spf} \; g }{ \Delta v }   }\)  

 

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Tags: Pressure Equations Water Hammer Equations