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

31 views (last 30 days)
Abdulrahman Al Baalharith
Abdulrahman Al Baalharith on 19 Nov 2019
Commented: Walter Roberson on 19 Nov 2019
midpoint function needed for the tm and Tm
  2 Comments
Abdulrahman Al Baalharith
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
Please follow these steps in completing this exercise and submit the
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

Sign in to comment.

Answers (1)

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

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!