Riview: Radiation Exchange between Surfaces ·The view factor Radiosity J Emissive Power(E) Reflective Power (Gret) Radiosity.J 4i→j Incident Radiation AJ G F4=A F A fraction of the total seen by Aj
Riview: Radiation Exchange between Surfaces • The view factor Radiosity , i j i j i i q F A J → = i J Emissive Power (E) Reflective Power (Gref) Fi, j Ai = AjFj,i A fraction of the total seen by Aj ρG E G
Blackbody Radiation Exchange qii=FiAJ q=FAJ If A &A are blackbody,no reflection, J=E=OT4 Net radiation heat transfer between the surfaces △q=FA,oI-FAoI, △9=FA,(T4-T)
• Blackbody Radiation Exchange i j i j i i q F A J → = , 4 J = Eb =σT j i j i j j q F A J → = , If Ai &Aj are blackbody, no reflection, Net radiation heat transfer between the surfaces 4 , 4 ij Fi, j Ai Ti Fj iAj Tj Δq = σ − σ ( ) 4 4 ij Fi, j Ai Ti Tj Δq = −
Electrical Resistance Analogy and network analysis enclosure 4 1 91 Eb 1/A Fi2 E62y92 1 W 2 3 42FG 9, Ep4 1/A4F3 Ev3 9 Fig.10.11
Electrical Resistance Analogy and network analysis
Lecture 12-13 Bioheat transfer Equations
Lecture 12-13 Bioheat transfer Equations
The Pennes Equation a)Experimental study-Temp mapping in the Human Forearm Subjects:Bare forearms of normotensive males (Neurological Institute) Environmental conditions: Room Temperature 25-27C Relative Humidity: 中。=62% Air:Free convection Measurement: T-type thermocouples J.A.P Vol.1No.2p.93-122,1948 H.H.Pennes Surface temp. Blood temp
The Pennes Equation a) Experimental study-Temp mapping in the Human Forearm Subjects: Bare forearms of normotensive males (Neurological Institute) Environmental conditions: Room Temperature 25-27 ℃ Relative Humidity: Air: Free convection Measurement: T-type thermocouples J.A.P Vol. 1 No.2 p.93-122, 1948 H.H.Pennes Surface temp. Blood temp. φ ∞ = 62%