<html><body><div style="color:#000; background-color:#fff; font-family:arial, helvetica, sans-serif;font-size:18pt"><div><span>Dear LEE</span></div><div><span></span> </div><span><div><b>Law 1. With impeller diameter (D) held constant:</b></div><div>Law 1a. Flow is proportional to shaft speed: </div><dl><dd><font color="#0645ad" size="2"><img class="tex" alt=" { Q_1 \over \ Q_2} = { \left ( {N_1 \over N_2} \right )} " src="http://upload.wikimedia.org/wikipedia/en/math/0/1/4/0144ae4d248986a4ef5fc7528b29447a.png"></font></dd></dl><div>Law 1b. Pressure or Head is proportional to the square of shaft speed:</div><dl><dd><img class="tex" alt=" {H_1 \over H_2} = { \left ( {N_1 \over N_2} \right )^2 }" src="http://upload.wikimedia.org/wikipedia/en/math/0/d/a/0dad552c48d31ca78cc7c27aa7d8e98d.png"></dd></dl><div>Law 1c. Power is proportional to the cube of shaft speed:</div><dl><dd><img class="tex" alt=" {P_1 \over P_2} = { \left ( {N_1 \over N_2} \right
)^3 }" src="http://upload.wikimedia.org/wikipedia/en/math/6/d/9/6d984734ca35921aa02fb60521f442bc.png"></dd></dl><div><b>Law 2. With shaft speed (N) held constant:</b></div><div>Law 2a. Flow is proportional to impeller diameter:</div><dl><dd><img class="tex" alt=" { Q_1 \over \ Q_2} = { \left ( {D_1 \over D_2} \right ) } " src="http://upload.wikimedia.org/wikipedia/en/math/d/9/e/d9ee1905ec39cf222b69b4d9ca77bb4c.png"></dd></dl><div>Law 2b. Pressure or Head is proportional to the square of impeller diameter:</div><dl><dd><img class="tex" alt=" {H_1 \over H_2} = { \left ( {D_1 \over D_2} \right )^2 }" src="http://upload.wikimedia.org/wikipedia/en/math/e/7/8/e7874035b640b0c2ded9bb149d21c55d.png"></dd></dl><div>Law 2c. Power is proportional to the cube of impeller diameter:</div><dl><dd><img class="tex" alt=" {P_1 \over P_2} = { \left ( {D_1 \over D_2} \right )^3 }"
src="http://upload.wikimedia.org/wikipedia/en/math/c/f/e/cfe05c4f62c963e048acedc3bbe66632.png"></dd></dl><div>where</div><ul><li><img class="tex" alt=" Q " src="http://upload.wikimedia.org/wikipedia/en/math/f/0/9/f09564c9ca56850d4cd6b3319e541aee.png"> is the volumetric flow rate (e.g. <a title="CFM" href="http://us.mg6.mail.yahoo.com/wiki/CFM"><font color="#0645ad">CFM</font></a>, GPM or L/s),</li><li><img class="tex" alt=" D " src="http://upload.wikimedia.org/wikipedia/en/math/f/6/2/f623e75af30e62bbd73d6df5b50bb7b5.png"> is the impeller diameter (e.g. in or mm),</li><li><img class="tex" alt=" N " src="http://upload.wikimedia.org/wikipedia/en/math/8/d/9/8d9c307cb7f3c4a32822a51922d1ceaa.png"> is the shaft rotational speed (e.g. <a class="mw-redirect" title="Rpm" href="http://us.mg6.mail.yahoo.com/wiki/Rpm"><font color="#0645ad">rpm</font></a>),</li><li><img class="tex" alt=" H "
src="http://upload.wikimedia.org/wikipedia/en/math/c/1/d/c1d9f50f86825a1a2302ec2449c17196.png"> is the pressure or head developed by the fan/pump (e.g. ft or m), and</li><li><img class="tex" alt=" P " src="http://upload.wikimedia.org/wikipedia/en/math/4/4/c/44c29edb103a2872f519ad0c9a0fdaaa.png"> is the shaft power (e.g. W).</li></ul><div> </div><div>Regards</div><div> </div><div>Nidal Abdalla</span></div><div><br></div> <div style="font-family: arial, helvetica, sans-serif; font-size: 18pt;"> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div dir="ltr"> <font size="2" face="Arial"> <div style="margin: 5px 0px; padding: 0px; border: 1px solid rgb(204, 204, 204); height: 0px; line-height: 0; font-size: 0px;" class="hr" contentEditable="false" readonly="true"></div> <b><span style="font-weight: bold;">From:</span></b> hankiat lee <leehankiat@hotmail.com><br> <b><span style="font-weight:
bold;">To:</span></b> trnsys-users@cae.wisc.edu <br> <b><span style="font-weight: bold;">Sent:</span></b> Monday, March 5, 2012 8:34 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> [TRNSYS-users] Variable Fan Power Coefficient<br> </font> </div> <br>
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<br>Hi all,<br><br>Do anybody know how to set the number of power coefficient and the values for each of the power coefficient in type 662, variable fan.<br><br>Thank You<br><br>Lee Han Kiat<br> </div></div>
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