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Question about Poisseuille's law and blood flow

  1. Sep 26, 2005 #1
    I know that rate of flow is equal to pi*(P1-P2)*R^4/8nL. For blood in the coronary artery, I know the pressure drop, and the radius of the artery. What is the viscosity of blood??? I can't find this value anywhere! And what value should I enter for L (distance L along a tube)? Is there an actual value somewhere for the length of the coronary artery in mm?
  2. jcsd
  3. Sep 27, 2005 #2


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    According to this source http://www.usc.edu/dept/biomed/bme403/Section_3/viscosity_of_blood.html [Broken]
    The value is approximately three times that of water. So if I use the dynamic viscosity of water at 20°C as
    [tex]\mu_{water} = 20.92 \frac{Lb_f sec}{ft^2}[/tex], that would mean that [tex]\mu_{blood} = 3.0 \mu_{water}[/tex] so...

    [tex]\mu_{blood}= 62.76 \frac{Lb_f sec}{ft^2}[/tex]

    [tex]\mu_{blood}= 3.0 x 10^6 cP [/tex]

    I can't really help you in terms of L in your equation. A couple of options would be to a)Leave L blank and express your answers in flow per unit length (which sounds kind of funny but is technically correct). or b)Make an estimation.
    Last edited by a moderator: May 2, 2017
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