An array of electronic chips is mounted within a sealedrectangular enclosure, and colling is implemented by attaching analuminum
heat sink (k=180 W/m*K). The base of the heat sinkhas dimensions of w1=w2=100mm, while the 6 fins are of thicknesst=10mm and pitch S=18mm. The fin length is Lf=50 mm, and thebase of the heat sink has a thickness of Lb=10mm.
If cooling is implemented by water flow through the heat sink,with u[infinity]=3 m/s and T[infinity]=17 C, what is the base temperatureTb of the heat sink when the power dissipation by the chips isPelec=1800W? The average convection coefficient for surfacesof the fins and the exposed base may be estimated by assumingparallel flow over a flat plate. Properties of the water maybe approximated as k=0.62 W/m*K, ν=7.73E-7 m2/s, andPr=5.2.
If cooling is implemented by water flow through the heat sink,with u[infinity]=3 m/s and T[infinity]=17 C, what is the base temperatureTb of the heat sink when the power dissipation by the chips isPelec=1800W? The average convection coefficient for surfacesof the fins and the exposed base may be estimated by assumingparallel flow over a flat plate. Properties of the water maybe approximated as k=0.62 W/m*K, ν=7.73E-7 m2/s, andPr=5.2.
1 answer:
You might be interested in
Answer:
The surface temperature is 921.95°C .
Explanation:
Given:
a=25 cm ,P=350 hp⇒P=260750 W
Power transmitted W and remaining will lost in the form of heat.This heat transmitted to air by the convection.
h=230
Actually heat will be transmit by the convection.
In convection Q=hA
So
T=921.95°C
So the surface temperature is 921.95°C .
Answer:
The expression is shown in the explanation below:
Explanation:
Thinking process:
Let the time period of a simple pendulum be given by the expression:
Let the fundamental units be mass= M, time = t, length = L
Then the equation will be in the form
where k is the constant of proportionality.
Now putting the dimensional formula:
Equating the powers gives:
a = 0
b + c = 0
2c = 1, c = -1/2
b = 1/2
so;
a = 0 , b = 1/2 , c = -1/2
Therefore:
T =
where k =