From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 1910/CH5/EX5.4/Chapter54.sce | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100755 1910/CH5/EX5.4/Chapter54.sce (limited to '1910/CH5/EX5.4/Chapter54.sce') diff --git a/1910/CH5/EX5.4/Chapter54.sce b/1910/CH5/EX5.4/Chapter54.sce new file mode 100755 index 000000000..5edd0e7b6 --- /dev/null +++ b/1910/CH5/EX5.4/Chapter54.sce @@ -0,0 +1,41 @@ +// Display mode +mode(0); +// Display warning for floating point exception +ieee(1); +clear; +clc; +disp("Introduction to heat transfer by S.K.Som, Chapter 5, Example 4") +//Air at atmospheric pressure is required to flow over a circuit board to cool the electronics element mounted on it. +//Chip has length (L)=3mm and width(B)=3mm located x=0.1m from the leading edge +L=0.003;//in metre +B=0.003;//in metre +x=0.1; +//The Nusselt no. is given by Nux=0.06*Rex^0.85*Pr^0.33 +//The chip has to dissipate E=50mW of energy while its surface temprature has to be kept below temprature,Ts=45°C and free strem Temptrature of air is Tinf=25°C +Ts=45; +Tinf=25; +E=50*10^-3;//in watt +//For air ,density(rho=1.2kg/m^3),viscosity(mu=1.8*10^5kg/(m*s)),conductivity(k=0.03W/(m*K)) and specific heat(cp=1000J/(kg*K)) +rho=1.2; +mu=1.8*10^5; +k=0.03; +cp=1000; +//Let the minimum flow velocity be U. +//The local heat transfer coefficient hx where the chip is mounted is determined as hx=(k/x)*0.06*(rho*U*x/mu)^0.85*(mu*cp/k)^0.33 +disp("The local heat transfer coefficient hx is hx=27.063*U^0.85") +//from an enrgy balance we can write 27.063*U^0.85*L*B*(Ts-Tinf)=E +disp("The minimum flow velocity in m/s is") +U=[E/(27.063*L*B*(Ts-Tinf))]^(1/0.85) + + + + + + + + + + + + + -- cgit