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Reynolds Number Calculator

Reynolds Number Calculator

This program calculates the Reynolds Number by entering in flow characteristics in circular conduits or pipe flows . It calculates the Reynolds number you might expect to determine if the fluid is acting in a laminar, transitional, or turbulent phase based on the Reynolds Number result. It is a simple calculation using a basic Reynolds textbook formula . 

{source}

<?php
/* Program name: ReynoldCalculator.php
* Description: Calculates Reynold Number
* Last Updated: 15 Oct 05
*/

// define default values
$Unit_index = 0;
$DistanceDiameter_value = “”;
$DistanceDiameterUnit_value = $Unit_index;
$PrevDistanceDiameterUnit_value = $Unit_index;
$FluidVelocity_value = “”;
$FluidVelocityUnit_value = $Unit_index;
$PrevFluidVelocityUnit_value = $Unit_index;
$FluidDensity_value = “”;
$FluidDensityUnit_value = $Unit_index;
$PrevFluidDensityUnit_value = $Unit_index;
$ViscosityUnit_value = “”;
$ViscosityUnit_value = $Unit_index;
$PrevViscosityUnit_value = $Unit_index;
$ReynoldsNumber_value = “”;

// define units
$DistanceDiameterUnits = array(“m”, “in”, “ft”, “cm”);
$DistanceDiameterUnitsNo = 3;
$FluidVelocityUnits = array(“m/s”, “cm/s”, “ft/s”, “mph”, “in/s”);
$FluidVelocityUnitsNo = 4;
$FluidDensityUnits = array(“kg/m3”, “lb/in3”, “kg/l”);
$FluidDensityUnitsNo = 2;
$ViscosityUnits = array(“cP”, “Pa-S”, “Kg/m-s”, “Slug/ft-s”);
$ViscosityUnitsNo = 3;

// define conversion rates
//meter to others
$DistanceDiameterConv[0][0] = 1;
$DistanceDiameterConv[0][1] = 39.3700787401575;
$DistanceDiameterConv[0][2] = 3.28083989501312;
$DistanceDiameterConv[0][3] = 100;
//inche to others
$DistanceDiameterConv[1][0] = 0.0254;
$DistanceDiameterConv[1][1] = 1;
$DistanceDiameterConv[1][2] = 0.0833333;
$DistanceDiameterConv[1][3] = 2.54;
//ft to others
$DistanceDiameterConv[2][0] = 0.3048;
$DistanceDiameterConv[2][1] = 12;
$DistanceDiameterConv[2][2] = 1;
$DistanceDiameterConv[2][3] = 30.48;
//cm to others
$DistanceDiameterConv[3][0] = 0.01;
$DistanceDiameterConv[3][1] = 0.393700874;
$DistanceDiameterConv[3][2] = 0.0328084;
$DistanceDiameterConv[3][3] = 1;
//m/sec to others
$FluidVelocityConv[0][0] = 1;
$FluidVelocityConv[0][1] = 100;
$FluidVelocityConv[0][2] = 3.2808399;
$FluidVelocityConv[0][3] = 2.2369363;
$FluidVelocityConv[0][4] = 39.3700787;
//cm/sec to others
$FluidVelocityConv[1][0] = 0.01;
$FluidVelocityConv[1][1] = 1;
$FluidVelocityConv[1][2] = 0.0328084;
$FluidVelocityConv[1][3] = 0.0223694;
$FluidVelocityConv[1][4] = 0.3937008;
//ft/sec to others
$FluidVelocityConv[2][0] = 0.3048;
$FluidVelocityConv[2][1] = 30.48;
$FluidVelocityConv[2][2] = 1;
$FluidVelocityConv[2][3] = 0.6818182;
$FluidVelocityConv[2][4] = 12;
//mph to others
$FluidVelocityConv[3][0] = 0.44704;
$FluidVelocityConv[3][1] = 44.704;
$FluidVelocityConv[3][2] = 1.4666667;
$FluidVelocityConv[3][3] = 1;
$FluidVelocityConv[3][4] = 17.6;
//in/s to others
$FluidVelocityConv[4][0] = 0.0254;
$FluidVelocityConv[4][1] = 2.54;
$FluidVelocityConv[4][2] = 0.0833333;
$FluidVelocityConv[4][3] = 0.0568182;
$FluidVelocityConv[4][4] = 1;
//Kg/m3 to others
$FluidDensityConv[0][0] = 1;
$FluidDensityConv[0][1] = 0.0000361;
$FluidDensityConv[0][2] = 0.001;
//lb/in3 to others
$FluidDensityConv[1][0] = 27700;
$FluidDensityConv[1][1] = 1;
$FluidDensityConv[1][2] = 27.7;
//kg/l to others
$FluidDensityConv[2][0] = 1000;
$FluidDensityConv[2][1] = 0.0361;
$FluidDensityConv[2][2] = 1;
//cP to others
$ViscosityConv[0][0] = 1;
$ViscosityConv[0][1] = 0.001;
$ViscosityConv[0][2] = 0.001;
$ViscosityConv[0][3] = 0.0000209;
//Pa-S to others
$ViscosityConv[1][0] = 1000;
$ViscosityConv[1][1] = 1;
$ViscosityConv[1][2] = 1;
$ViscosityConv[1][3] = 0.0208854;
//Kg/m-s to others
$ViscosityConv[2][0] = 1000;
$ViscosityConv[2][1] = 1;
$ViscosityConv[2][2] = 1;
$ViscosityConv[2][3] = 0.0208854;
//Slug/ft-s to others
$ViscosityConv[3][0] = 47900;
$ViscosityConv[3][1] = 47.9;
$ViscosityConv[3][2] = 47.880259;
$ViscosityConv[3][3] = 1;

// get selected units
if (@$_POST[‘DistanceDiameterUnit’] != “”)
{
$DistanceDiameterUnit_value = $_POST[‘DistanceDiameterUnit’];
}
else
{
$_POST[‘DistanceDiameterUnit’] = $Unit_index;
}
if (@$_POST[‘PrevDistanceDiameterUnit’] != “”)
{
$PrevDistanceDiameterUnit_value = $_POST[‘PrevDistanceDiameterUnit’];
}
else
{
$_POST[‘PrevDistanceDiameterUnit’] = $Unit_index;
}
if (@$_POST[‘FluidVelocityUnit’] != “”)
{
$FluidVelocityUnit_value = $_POST[‘FluidVelocityUnit’];
}
else
{
$_POST[‘FluidVelocityUnit’] = $Unit_index;
}
if (@$_POST[‘PrevFluidVelocityUnit’] != “”)
{
$PrevFluidVelocityUnit_value = $_POST[‘PrevFluidVelocityUnit’];
}
else
{
$_POST[‘PrevFluidVelocityUnit’] = $Unit_index;
}
if (@$_POST[‘FluidDensityUnit’] != “”)
{
$FluidDensityUnit_value = $_POST[‘FluidDensityUnit’];
}
else
{
$_POST[‘FluidDensityUnit’] = $Unit_index;
}
if (@$_POST[‘PrevFluidDensityUnit’] != “”)
{
$PrevFluidDensityUnit_value = $_POST[‘PrevFluidDensityUnit’];
}
else
{
$_POST[‘PrevFluidDensityUnit’] = $Unit_index;
}
if (@$_POST[‘ViscosityUnit’] != “”)
{
$ViscosityUnit_value = $_POST[‘ViscosityUnit’];
}
else
{
$_POST[‘ViscosityUnit’] = $Unit_index;
}
if (@$_POST[‘PrevViscosityUnit’] != “”)
{
$PrevViscosityUnit_value = $_POST[‘PrevViscosityUnit’];
}
else
{
$_POST[‘PrevViscosityUnit’] = $Unit_index;
}

switch (@$_POST[‘Calculate’])
{
case “0”: // conversion for Distance/Diameter
if (@$_POST[‘DistanceDiameter’] != “”)
{
if ($DistanceDiameterUnit_value != $PrevDistanceDiameterUnit_value)
{
$DistanceDiameter_value = $DistanceDiameterConv[$PrevDistanceDiameterUnit_value][$DistanceDiameterUnit_value] * $_POST[‘DistanceDiameter’];
$_POST[‘DistanceDiameter’] = sprintf(‘%0.8f’, $DistanceDiameter_value);
}
$_POST[‘PrevDistanceDiameterUnit’] = $DistanceDiameterUnit_value;
}
break;

case “1”: // conversion for Fluid Velocity
if (@$_POST[‘FluidVelocity’] != “”)
{
if ($FluidVelocityUnit_value != $PrevFluidVelocityUnit_value)
{
$FluidVelocity_value = $FluidVelocityConv[$PrevFluidVelocityUnit_value][$FluidVelocityUnit_value] * $_POST[‘FluidVelocity’];
$_POST[‘FluidVelocity’] = sprintf(‘%0.8f’, $FluidVelocity_value);
}
$_POST[‘PrevFluidVelocityUnit’] = $FluidVelocityUnit_value;
}
break;

case “2”: // conversion for Fluid Density
if (@$_POST[‘FluidDensity’] != “”)
{
if ($FluidDensityUnit_value != $PrevFluidDensityUnit_value)
{
$FluidDensity_value = $FluidDensityConv[$PrevFluidDensityUnit_value][$FluidDensityUnit_value] * $_POST[‘FluidDensity’];
$_POST[‘FluidDensity’] = sprintf(‘%0.8f’, $FluidDensity_value);
}
$_POST[‘PrevFluidDensityUnit’] = $FluidDensityUnit_value;
}
break;

case “3”: // conversion for Viscosity
if (@$_POST[‘Viscosity’] != “”)
{
if ($ViscosityUnit_value != $PrevViscosityUnit_value)
{
$Viscosity_value = $ViscosityConv[$PrevViscosityUnit_value][$ViscosityUnit_value] * $_POST[‘Viscosity’];
$_POST[‘Viscosity’] = sprintf(‘%0.8f’, $Viscosity_value);
}
$_POST[‘PrevViscosityUnit’] = $ViscosityUnit_value;
}
break;

case “Calculate”: // calculate
// Calculate Flowrate
if (@$_POST[‘DistanceDiameter’] != “” and @$_POST[‘FluidVelocity’] != “” and @$_POST[‘FluidDensity’] != “” and @$_POST[‘Viscosity’] != “”)
{
// Convert Distance/Diameter to base unit
$DistanceDiameter_value = $DistanceDiameterConv[$DistanceDiameterUnit_value][0] * $_POST[‘DistanceDiameter’];
// Convert Fluid Velocity to base unit
$FluidVelocity_value = $FluidVelocityConv[$FluidVelocityUnit_value][0] * $_POST[‘FluidVelocity’];
// Convert Fluid Density to respective unit
$FluidDensity_value = $FluidDensityConv[$FluidDensityUnit_value][0] * $_POST[‘FluidDensity’];
// Convert Viscosity to respective unit
$Viscosity_value = $ViscosityConv[$ViscosityUnit_value][2] * $_POST[‘Viscosity’];
// Calculate Reynolds Number
$ReynoldsNumber_value = ($DistanceDiameter_value * $FluidVelocity_value * $FluidDensity_value) / $Viscosity_value;
$_POST[‘ReynoldsNumber’] = sprintf(‘%0.6f’, $ReynoldsNumber_value);
}
break;

case “Reset”: // reset
$_POST[‘DistanceDiameter’] = “”;
$_POST[‘FluidVelocity’] = “”;
$_POST[‘FluidDensity’] = “”;
$_POST[‘Viscosity’] = “”;
$_POST[‘ReynoldsNumber’] = “”;
break;
}
?>

<?php
echo “<html>
<head><title>Reynolds Calculator</title></head>
<meta http-equiv=’Content-Type’ content=’text/html; charset=iso-8859-1′>
<META NAME=’description’ CONTENT=’Flowmeter Directory Flow meters manufacturers of magnetic turbine vortex venturi multiphase open channel variable area liquid and gas flowmeters’>
<META NAME=’keywords’ CONTENT=’Coriolis Mass,Electromagnetic Magnetic,Multiphase,Orifice plate,Positive Displacement,Target,Turbine,Thermal Mass,Ultrasonic , Venturi, Vortex shedding,flowmeter,flowmeters,flow meter,open channel,meters,measurement,directory,list ‘>
<style type=’text/css’>
<!–
body { margin: 0px 0px; padding: 0px 0px}

.size10pt { font-family: Arial, Helvetica, sans-serif; font-size: 10px}
.size12pt { font-family: Arial, Helvetica, sans-serif; font-size: 12px}
.size14pt { font-family: Arial, Helvetica, sans-serif; font-size: 14px}
.size16pt { font-family: Arial, Helvetica, sans-serif; font-size: 16px}
–>
</style>

<script src=AC_RunActiveContent.js type=text/javascript></script>
</head>”

?>

<style type=”text/css”>
<!–
.size12pt {font-family: Arial, Helvetica, sans-serif; font-size: 12px}
.style8 {color: #FFFFFF}
–>
</style>

<body bgcolor=”#FFFFFF”>
<table width=”100%” border=”0″ cellspacing=”0″ cellpadding=”5″>
<tr>
<td valign=”top”><form name=”Calculator” method=”POST”>
<input type=”hidden” name=”Calculate” value=”Calculate”>
<table border=”0″ cellspacing=”0″ cellpadding=”2″>
<tr>
<td><b>Distance/Diameter:</b></td>
<td><input type=”text” name=”DistanceDiameter” value=”<?php echo @$_POST[‘DistanceDiameter’]?>”></td>
<td>
<input type=”hidden” name=”PrevDistanceDiameterUnit” value=”<?php echo @$_POST[‘PrevDistanceDiameterUnit’]?>”>
<select name=”DistanceDiameterUnit” onChange=”self.document.Calculator.Calculate.value=’0′;self.document.Calculator.submit()” style=”width: 80; “>
<?php
for ($i=0;$i<=$DistanceDiameterUnitsNo;$i++)
{
echo “<option value=’$i'”;
if (@$_POST[‘DistanceDiameterUnit’] == $i)
{
echo ” selected”;
}
echo “>$DistanceDiameterUnits[$i]</option>\n”;
}
?>
</select>
</td>
</tr>
<tr>
<td><b>Fluid Velocity:</b></td>
<td><input type=”text” name=”FluidVelocity” value=”<?php echo @$_POST[‘FluidVelocity’]?>”></td>
<td>
<input type=”hidden” name=”PrevFluidVelocityUnit” value=”<?php echo @$_POST[‘PrevFluidVelocityUnit’]?>”>
<select name=”FluidVelocityUnit” onChange=”self.document.Calculator.Calculate.value=’1′;self.document.Calculator.submit()” style=”width: 80; “>
<?php
for ($i=0;$i<=$FluidVelocityUnitsNo;$i++)
{
echo “<option value=’$i'”;
if (@$_POST[‘FluidVelocityUnit’] == $i)
{
echo ” selected”;
}
echo “>$FluidVelocityUnits[$i]</option>\n”;
}
?>
</select>
</td>
</tr>
<tr>
<td><b>Fluid Density:</b></td>
<td><input type=”text” name=”FluidDensity” value=”<?php echo @$_POST[‘FluidDensity’]?>”></td>
<td>
<input type=”hidden” name=”PrevFluidDensityUnit” value=”<?php echo @$_POST[‘PrevFluidDensityUnit’]?>”>
<select name=”FluidDensityUnit” onChange=”self.document.Calculator.Calculate.value=’2′;self.document.Calculator.submit()” style=”width: 80; “>
<?php
for ($i=0;$i<=$FluidDensityUnitsNo;$i++)
{
echo “<option value=’$i'”;
if (@$_POST[‘FluidDensityUnit’] == $i)
{
echo ” selected”;
}
echo “>$FluidDensityUnits[$i]</option>\n”;
}
?>
</select>
</td>
</tr>
<tr>
<td><b>Viscosity:</b></td>
<td><input type=”text” name=”Viscosity” value=”<?php echo @$_POST[‘Viscosity’]?>”></td>
<td>
<input type=”hidden” name=”PrevViscosityUnit” value=”<?php echo @$_POST[‘PrevViscosityUnit’]?>”>
<select name=”ViscosityUnit” onChange=”self.document.Calculator.Calculate.value=’3′;self.document.Calculator.submit()” style=”width: 80; “>
<?php
for ($i=0;$i<=$ViscosityUnitsNo;$i++)
{
echo “<option value=’$i'”;
if (@$_POST[‘ViscosityUnit’] == $i)
{
echo ” selected”;
}
echo “>$ViscosityUnits[$i]</option>\n”;
}
?>
</select>
</td>
</tr>
<tr>
<td><b>Reynolds Number R:</b></td>
<td><?php echo @$_POST[‘ReynoldsNumber’]?></td>
<td></td>
</tr>
</table>
<p><input type=”submit” value=”Calculate”>&nbsp;&nbsp;
<input type=”button” value=”Reset” onClick=”self.document.Calculator.Calculate.value=’Reset’;self.document.Calculator.submit()”></p>
</form></td>
</tr>
</table>
</body>
</html>

{/source}

Reynolds Number Calculator

 

This reynolds number calculation is  for circular conduits/pipes. Pipe roughness which can have a small effect on the calculation has not been considered in the calculation on this page,

For more discussions and calculations regarding Reynolds number calculations for other applications e.g aeronautical

http://www.grc.nasa.gov/WWW/BGH/reynolds.html

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