• Next Tuesday (March 12 th ). Department meeting.
– Ms. Liron’s office hours start at 2:15pm
• TAKE NOTES! fill in the blanks!
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• Library functions: ceil() , floor() , round() , mod()
• Loops
– while
– for
• Arrays
– Create: [] , rand()
– Analyze: sum() , prod() , min() , max() , mean()
– Dimensioning: length() , size() , numel()
– Slicing/referencing: vector(k) , matrix(r,c), array(_:_)
– Concatenating: []
– Traversing: for k = 1:____
– Deleting: =[];
• Plotting basics
– plot(x,y) %plots y vs. x graph
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• AE 315 Experimental Aerodynamics Lab
Source: http://wings.avkids.com/Tennis/Images/ten_wt.jpg

• Soruce: http://www.aerolab.com/Display_Pages/EWT.html

• The photograph shows a stainless steel model of a Mk I which was used in 1941 for wind tunnel investigations into high speed dive characteristics.
 NASA wind tunnel
Source: http://wpcontent.answers.com/wikipedia/commons/thumb/0/04/Win dkanal.jpg/350px-Windkanal.jpg

• Helios wind tunnel model
Source: http://www.speedace.info/solar_cars/aristotle_univ ersity_of_thessaloniki_helios.htm
 Formula1 cars
Source: http://www.lucamazzocco.com/images_all.asp
?CategoryID=42

• This is the motivation for the realization of an extensive wind tunnel model of the city part
"Kleinbasel" at the scale
1:300. The model covers an area of a bit less than 3 km² of urban roughness densely covered by over 3 200 houses as it is typical for
Basel and other european urban environments of comparable size.
Source: http://pages.unibas.ch/geo/mcr/Projects/BUBBLE/textpages/md_windtunnel.en.htm

• What happens to the water in a tube?

Source: http://technicalteachingequipment.com/images/Aerodynamics%20lab/wind%20tunnel%20panel%20board%20with%20manometer.JPG

Source: http://technicalteachingequipment.com/images/Aerodynamics%20lab/wind%20tunnel%20panel%20board%20with%20manometer.JPG

Source: http://www.aerolab.
com/Display_Pages
/EWT.html
Source: http://www.sewon-eng.co.kr/Brand_img/185_A.jpg
Source: http://www.cussons.c
o.uk/en/products/p32
02.html

• Velocity is linked to the pressure in the tube
𝑉 𝑓𝑡 𝑠
= 2.905 ∗ 𝑃 𝑡
− 𝑃 𝑠
∗ 𝑇
– Where 𝑃 𝑡 is the total pressure (in inches of water)
– Where 𝑃 𝑠 is the static pressure (in inches of water). That is the reference point of the tube, when the wind tunnel is off.
– 𝑇 is the absolute air temperature in Rankine (not Celsius, not
Fahrenheit).
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• Assume the static pressure is 32 inches, and the temperature is 78F
(537Rankine)
• Let the user indicate how many pitot tubes were recorded. Trap when invalid. It should be above 5.
• Loop to generate the table of data. Store all data in one array, as values are calculated .
– Total pressure: prompt user number between 30 and 32 inches.
• (Assume valid inputs given at this time) 𝑓𝑡
– Calculate velocity associated each time
𝑉 𝑠
= 2.905 ∗ 𝑃 𝑡
− 𝑃 𝑠
• Display the table, with headers.
• Plot the local velocities vs. the pitot tube number
• Calculate the min, max, and average velocity.
∗ 𝑇
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• These are just guidelines
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• Keywords?
• Algorithm ideas?
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clc clear
… develop your algorithm please!
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clc clear
%set up constant data
%prompt user for nb of tubes
_______________________________ while _______________________________
_______________________________ end
%loop for each tube for _______________________________
%store tube number in column 1
_______________________________
%generate water height (32-35), store in column2
_______________________________
%calculate velocity, store in column3
_______________________________ end
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%display header
___________________________________________________________________________________
%display table
___________________________________________________________________________________
%plot velocity vs. tube number
____________________________________________________
____________________________________________________
____________________________________________________
%find min, max, average
____________________________________________________
____________________________________________________
____________________________________________________
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• Assume the static pressure is 32 inches, and the temperature is 78F (537Rankine)
• Let the user indicate how many pitot tubes were recorded.
Trap when invalid. It should be above 5.
• Without a loop , create the table.
– Total pressure: Generate random floats between 30 and 32 inches.
• Display the table with headers.
• Plot the local velocities vs. the pitot tube number
• Calculate the min, max, and average velocity.
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clc clear
%set up constant data
%prompt user for nb of tubes while end
% create column of tube number
% generate column of water height (32-35)
% calculate velocity
% combine all columns into 1 table
%display header
%display table
%plot velocity vs. tube number
%find min, max, average
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• Practice tonight.
• Take the notes you just took, and code the example!
• The more practice, the easier it gets!
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