# Create array tm and Tm corresponding to the midpoints of t and T Temperature steps

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midpoint function needed for the tm and Tm
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Abdulrahman Al Baalharith on 19 Nov 2019
Problem 4:
Heat Transfer coefficient estimation in a quenching experiment simulation
with the aid of MATLAB
You are required to compute the estimated heat transfer coefficient (h)
data for an Inconel thermocouple mounted at the center face of a cylindrical
probe. The hot probe is dunked into a quench tank containing Canola Oil at a
temperature of Ts
Key data for the probe:
Material: Inconel
Density (ρ) = 8470 kg/m3
Diameter = 15 mm
Length = 45 mm
Specific heat capacity (cp) = 4184 J/kg oC
Temperature of the Canola oil in the quench tank is Ts = 21 oC
Important relationships to incorporate in your computations
Heat lost by the probe = qA = h*A*(Tm-Ts)
Decrease in internal energy of the probe = qm = - *V*cp*cr
Under equilibrium conditions qA = qm. Solve for h as a function of time, time
being the midstep time, tm
Where:
h = heat transfer coefficient
cr = the cooling rate determined as delT/delt
A = the surface area of the probe.
V = volume of the probe
4 | P a g e
materials requested.
 Read the Canola Oil sheet from the RDData.xlsx file from the data
folder of D2L
 Assign the first column to ‘t’, and the second column to ‘T’
 Create new arrays ‘delt’ and ‘delT’ as the mid-step values computed
from ‘t’ as delt = (t(n)-t(n-1)) and delT = (T(n)-T(n-1)). As a check, delt
will have positive values and delT will be negative values. With
negative delT values, the negative sign in the qm term will be flipped to
a positive one, resulting in positive values for h. ‘n’ is a subscript that
you could use to keep track entries of the time and temperature
arrays.
 You will need to use ‘delt’; and delT’ in computing and visualizing ‘h’
 Create a cooling rate array cr = delT/delt
 Create array tm and Tm corresponding to the midpoints of t and T
Temperature steps
 Code the equation for computing h
 Generate a plot of T versus t
 Generate a plot of h versus tm

Walter Roberson on 19 Nov 2019
tm = t(1:end-1) + delt/2
where delt is the vector we discussed in your previous Question.
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Walter Roberson on 19 Nov 2019
delt = diff(t);
delT = diff(T);
tm = t(1:end-1) + delt/2;
tM = T(1:end-1) + delT/2;