while loop index exceeds array elements problem

I am trying to run multiple iterations of this while loop to determine the reynolds number for various mass flow rates.. The first loop works perfectly, but when it gets to the second loop it gives me the error "Index exceeds array elements (1)" which is odd because I set up both loops the same way.. I tried reloading matlab but got the same

[DGM]

Can you paste the actual text. I'm not eager to re-type everything from a picture and then guess which errors are caused by my own typos.

[mason beal]

i will but the code has variable brought in so your code wont run regardless cause they wont be in your workspace.

while abs(errorF30N) > 10^(-6)

M2 = 2*L2/(1-BN);

CNF30N= 0.99 - (0.2262*BN^(4.1))-(0.00175*BN^2-0.0033*BN^4.125)*(10^6/REF30N(i))^1.15;

MFRF30N = CNF30N*KN*A3*sqrt(2*ADF30N*F30NV);

REF30N(i+1) = 4*MFRF30N/(3.14159*AV*D1);

errorF30N=REF30N(i+1)-REF30N(i);

i = i+1;

end

while abs(errorF40N) > 10^(-6)

M2 = 2*L2/(1-BN);

CNF40N= 0.99 - (0.2262*BN^(4.1))-(0.00175*BN^2-0.0033*BN^4.125)*(10^6/REF40N(i))^1.15;

MFRF40N = CNF40N*KN*A3*sqrt(2*ADF40N*F40NV);

REF40N(i+1) = 4*MFRF30N/(3.14159*AV*D1);

errorF40N=REF40N(i+1)-REF40N(i);

i = i+1;

end

[mason beal]

Any help is appreciated though thank you.

[mason beal]

This is the complete monster

%Extract Temperature Values

F0NT=sum(F0N{:,2})/16;

F30NT=sum(F30N{:,2})/17;

F40NT=sum(F40N{:,2})/17;

F50NT=sum(F50N{:,2})/19;

F70NT=sum(F70N{:,2})/15;

F80NT=sum(F80N{:,2})/18;

F0OT=sum(F0O{:,2})/23;

F30OT=sum(F30O{:,2})/20;

F40OT=sum(F40O{:,2})/17;

F50OT=sum(F50O{:,2})/19;

F70OT=sum(F70O{:,2})/17;

F80OT=sum(F80O{:,2})/20;

%Extract Pressure difference values in Pa

F0NV=sum(F0N{:,12}./3.47.*248.84)/16;

F30NV=sum(F30N{:,12}./3.47.*248.84)/17;

F40NV=sum(F40N{:,12}./3.47.*248.84)/17;

F50NV=sum(F50N{:,12}./3.47.*248.84)/19;

F70NV=sum(F70N{:,12}./3.47.*248.84)/15;

F80NV=sum(F80N{:,12}./3.47.*248.84)/18;

F0OV=sum(F0O{:,12}./3.47.*248.84)/23;

F30OV=sum(F30O{:,12}./3.47.*248.84)/20;

F40OV=sum(F40O{:,12}./3.47.*248.84)/17;

F50OV=sum(F50O{:,12}./3.47.*248.84)/19;

F70OV=sum(F70O{:,12}./3.47.*248.84)/17;

F80OV=sum(F80O{:,12}./3.47.*248.84)/20;

%% calculations

%Determine input variables

D1=input('what is the Duct Diameter? mm');

D2=input('What is the Oriface Diameter? mm');

D3=input('What is the Nozzle Diameter? mm');

P=input('What is the Barametric Pressure? kPa');

%Convert Diameters

D1= D1/1000; %m

D2= D2/1000; %m

D3=D3/1000;

%Convert pressure

P= P*1000; %Pa

T=22.67;

%Determine intermediate variables

R = 287; %J/kg*K

A3 = (pi*(D3^2))/4;

A1 = (pi*(D1^2))/4; %duct area

A2 = (pi*(D2^2))/4; %orifice area

B=D2/D1;

BN = D3/D1; %diameter ratio

K = 1/((1-(B^4))^(1/2)); %velocity of approach factor

KN = 1/((1-(BN^4))^(1/2)); %velocity of approach factor

ADF0N = P/(R*(F0NT+273)); %air density

ADF30N = P/(R*(F30NT+273)); %air density

ADF40N = P/(R*(F40NT+273)); %air density

ADF50N = P/(R*(F50NT+273)); %air density

ADF70N = P/(R*(F70NT+273)); %air density

ADF80N = P/(R*(F80NT+273)); %air density

ADF0O = P/(R*(F0OT+273)); %air density

ADF30O = P/(R*(F30OT+273)); %air density

ADF40O = P/(R*(F40OT+273)); %air density

ADF50O = P/(R*(F50OT+273)); %air density

ADF70O = P/(R*(F70OT+273)); %air density

ADF80O = P/(R*(F80OT+273)); %air density

AV= (-0.2454*(T^2) +474.4064*T +1.7295e+05)*(10^-10); %absolute viscosity

KV = AV/AD; %kinematic viscosity

e=2.71828;

%% Discharge Coefficients

%% Reynolds number, MFR, VFR

%loop setup

i = 1; %initialize

%Initialize

errorF0N=1;

errorF30N=1;

errorF40N=1;

errorF50N= 1;

errorF70N=1;

errorF80N=1;

errorF0O=1;

errorF30O=1;

errorF40O=1;

errorF50O=1;

errorF70O=1;

errorF80O=1;

REF0N(i) = 10^8; %Reynolds number approximation

REF30N(i)= 10^8; %Reynolds number approximation

REF40N(i) = 10^8; %Reynolds number approximation

REF50N(i) = 10^8; %Reynolds number approximation

REF70N(i) = 10^8; %Reynolds number approximation

REF80N(i) = 10^8; %Reynolds number approximation

REF0O(i) = 10^8; %Reynolds number approximation

REF30O(i)= 10^8; %Reynolds number approximation

REF40O(i) = 10^8; %Reynolds number approximation

REF50O(i) = 10^8; %Reynolds number approximation

REF70O(i) = 10^8; %Reynolds number approximation

REF80O(i)= 10^8; %Reynolds number approximation

L2 = 0;

L1 = 0;

%Reynolds number determination loop

while abs(errorF30N) > 10^(-6)

M2 = 2*L2/(1-BN);

CNF30N= 0.99 - (0.2262*BN^(4.1))-(0.00175*BN^2-0.0033*BN^4.125)*(10^6/REF30N(i))^1.15;

MFRF30N = CNF30N*KN*A3*sqrt(2*ADF30N*F30NV);

REF30N(i+1) = 4*MFRF30N/(3.14159*AV*D1);

errorF30N=REF30N(i+1)-REF30N(i);

i = i+1;

end

while abs(errorF40N) > 10^(-6)

M2 = 2*L2/(1-BN);

CNF40N= 0.99 - (0.2262*BN^(4.1))-(0.00175*BN^2-0.0033*BN^4.125)*(10^6/REF40N(i))^1.15;

MFRF40N = CNF40N*KN*A3*sqrt(2*ADF40N*F40NV);

REF40N(i+1) = 4*MFRF30N/(3.14159*AV*D1);

errorF40N=REF40N(i+1)-REF40N(i);

i = i+1;

end

while abs(errorF50N) > 10^(-6)

M2 = 2*L2/(1-BN);

CNF50N= 0.99 - (0.2262*BN^(4.1))-(0.00175*BN^2-0.0033*BN^4.125)*(10^6/REF50N(i))^1.15;

MFRF50N = CNF50N*KN*A3*sqrt(2*ADF50N*F50NV);

REF50N(i+1) = 4*MFRF50N/(3.14159*AV*D1);

errorF50N=REF50N(i+1)-REF50N(i);

i = i+1;

end

while abs(errorF70N) > 10^(-6)

M2 = 2*L2/(1-BN);

CNF70N= 0.99 - (0.2262*BN^(4.1))-(0.00175*BN^2-0.0033*BN^4.125)*(10^6/REF70N(i))^1.15;

MFRF70N = CNF70N*KN*A3*sqrt(2*ADF70N*F70NV);

REF70N(i+1) = 4*MFRF70N/(3.14159*AV*D1);

errorF70N=REF70N(i+1)-REF70N(i);

i = i+1;

end

while abs(errorF80N) > 10^(-6)

M2 = 2*L2/(1-BN);

CNF80N= 0.99 - (0.2262*BN^(4.1))-(0.00175*BN^2-0.0033*BN^4.125)*(10^6/REF80N(i))^1.15;

MFRF80N = CNF80N*KN*A3*sqrt(2*ADF80N*F80NV);

REF80N(i+1) = 4*MFRF80N/(3.14159*AV*D1);

errorF80N=REF80N(i+1)-REF80N(i);

i = i+1;

end

while abs(errorF0O) > 10^(-6)

M2 = 2*L2/(1-B);

CF0O = 0.5961 + (0.0261*B^2)-(0.216*B^8)+(0.000521*(((10^6*B)/REF0O(i))^.7))+((0.0188+0.0063*A1)*B^3.5*(10^6/REF0O(i))^0.3)+((0.043+0.08*e^(10*L1)-0.123*e^(-7*L1))*(1-11*A1)*(B^4/(1-B^4)))- 0.31*(M2-0.8*M2^1.1)*B^1.3;

MFRF0O = CF0O*K*A2*sqrt(2*ADF0O*F0OV);

REF0O(i+1) = 4*MFRF0O/(3.14159*AV*D1);

errorF0O=REF0O(i+1)-REF0O(i);

i = i+1;

end

while abs(errorF30O) > 10^(-6)

M2 = 2*L2/(1-B);

CF30O = 0.5961 + (0.0261*B^2)-(0.216*B^8)+(0.000521*(((10^6*B)/REF30O(i))^.7))+((0.0188+0.0063*A1)*B^3.5*(10^6/REF30O(i))^0.3)+((0.043+0.08*e^(10*L1)-0.123*e^(-7*L1))*(1-11*A1)*(B^4/(1-B^4)))- 0.31*(M2-0.8*M2^1.1)*B^1.3;

MFRF30O = CF30O*K*A2*sqrt(2*ADF30O*F30OV);

REF30O(i+1) = 4*MFRF30O/(3.14159*AV*D1);

errorF30O=REF30O(i+1)-REF30O(i);

i = i+1;

end

while abs(errorF40O) > 10^(-6)

M2 = 2*L2/(1-B);

CF40O = 0.5961 + (0.0261*B^2)-(0.216*B^8)+(0.000521*(((10^6*B)/REF40O(i))^.7))+((0.0188+0.0063*A1)*B^3.5*(10^6/REF40O(i))^0.3)+((0.043+0.08*e^(10*L1)-0.123*e^(-7*L1))*(1-11*A1)*(B^4/(1-B^4)))- 0.31*(M2-0.8*M2^1.1)*B^1.3;

MFRF40O = CF40O*K*A2*sqrt(2*ADF40O*F40OV);

REF40O(i+1) = 4*MFRF40O/(3.14159*AV*D1);

errorF40O=REF40O(i+1)-REF40O(i);

i = i+1;

end

while abs(errorF50O) > 10^(-6)

M2 = 2*L2/(1-B);

CF50O = 0.5961 + (0.0261*B^2)-(0.216*B^8)+(0.000521*(((10^6*B)/REF50O(i))^.7))+((0.0188+0.0063*A1)*B^3.5*(10^6/REF50O(i))^0.3)+((0.043+0.08*e^(10*L1)-0.123*e^(-7*L1))*(1-11*A1)*(B^4/(1-B^4)))- 0.31*(M2-0.8*M2^1.1)*B^1.3;

MFRF50O = CF50O*K*A2*sqrt(2*ADF50O*F50OV);

REF50O(i+1) = 4*MFRF50O/(3.14159*AV*D1);

errorF50O=REF50O(i+1)-REF50O(i);

i = i+1;

end

while abs(errorF70O) > 10^(-6)

M2 = 2*L2/(1-B);

CF70O = 0.5961 + (0.0261*B^2)-(0.216*B^8)+(0.000521*(((10^6*B)/REF70O(i))^.7))+((0.0188+0.0063*A1)*B^3.5*(10^6/REF70O(i))^0.3)+((0.043+0.08*e^(10*L1)-0.123*e^(-7*L1))*(1-11*A1)*(B^4/(1-B^4)))- 0.31*(M2-0.8*M2^1.1)*B^1.3;

MFRF70O = CF70O*K*A2*sqrt(2*ADF70O*F70OV);

REF70O(i+1) = 4*MFRF70O/(3.14159*AV*D1);

errorF70O=REF70O(i+1)-REF70O(i);

i = i+1;

end

while abs(errorF80O) > 10^(-6)

M2 = 2*L2/(1-B);

CF80O = 0.5961 + (0.0261*B^2)-(0.216*B^8)+(0.000521*(((10^6*B)/REF80O(i))^.7))+((0.0188+0.0063*A1)*B^3.5*(10^6/REF80O(i))^0.3)+((0.043+0.08*e^(10*L1)-0.123*e^(-7*L1))*(1-11*A1)*(B^4/(1-B^4)))- 0.31*(M2-0.8*M2^1.1)*B^1.3;

MFRF80O = CF80O*K*A2*sqrt(2*ADF80O*F80OV);

REF80O(i+1) = 4*MFRF80O/(3.14159*AV*D1);

errorF80O=REF80O(i+1)-REF80O(i);

i = i+1;

end

while abs(errorF0N) > 10^(-6)

M2 = 2*L2/(1-B);

CNF0N= 0.99 - (0.2262*BN^(4.1))-(0.00175*BN^2-0.0033*BN^4.125)*(10^6/REF0N(i))^1.15;

MFRF0N = CNF0N*KN*A3*sqrt(2*ADF0N*F0NV);

REF0N(i+1) = 4*MFRF0N/(3.14159*AV*D1);

errorF0N= REF0N(i+1)-REF0N(i);

i = i+1;

end

L_REF0N= length(REF0N);

L_REF30N= length(REF30N);

L_REF40N= length(REF40N);

L_REF50N= length(REF50N);

L_REF70N= length(REF70N);

L_REF80N= length(REF80N);

L_REF0O= length(REF0O);

L_REF30O= length(REF30O);

L_REF40O= length(REF40O);

L_REF50O= length(REF50O);

L_REF70O= length(REF70O);

L_REF80O= length(REF80O);

F_REF0N= REF0N(L_REF0N);

F_REF30N= REF30N(L_REF30N);

F_REF40N= REF40N(L_REF40N);

F_REF50N= REF50N(L_REF50N);

F_REF70N= REF70N(L_REF70N);

F_REF80N= REF80N(L_REF80N);

F_REF0O= REF0O(L_REF0O);

F_REF30O= REF30O(L_REF30O);

F_REF40O= REF40O(L_REF40O);

F_REF50O= REF50O(L_REF50O);

F_REF70O= REF70O(L_REF70O);

F_REF80O= REF80O(L_REF80O);

%calcs

unc = ((5/3)*B-0.5)/100; %relative uncertainty

VFRF0N = MFRF0N/ADF0N; %volumetric flow rate in metric

VFRF30N = MFRF30N/ADF30N; %volumetric flow rate in metric

VFRF40N = MFRF40N/ADF40N; %volumetric flow rate in metric

VFRF50N = MFRF50N/ADF50N; %volumetric flow rate in metric

VFRF70N = MFRF70N/ADF70N; %volumetric flow rate in metric

VFRF80N = MFRF80N/ADF80N; %volumetric flow rate in metric

VFRF0O = MFRF0O/ADF0O; %volumetric flow rate in metric

VFRF30O = MFRF30O/ADF30O; %volumetric flow rate in metric

VFRF40O = MFRF40O/ADF40O; %volumetric flow rate in metric

VFRF50O = MFRF50O/ADF50O; %volumetric flow rate in metric

VFRF70O = MFRF70O/ADF70O; %volumetric flow rate in metric

VFRF80O = MFRF80O/ADF80O; %volumetric flow rate in metric

vel = VFR/A1; %average duct velocity

%% plot setup

NozP1 = [F0NV,F30NV,F40NV,F50NV,F70NV,F80NV];

OriP1 = [F0OV F30OV F40OV F50OV F70OV F80OV];

NozP=NozP1(1,:);

OriP=OriP1(1,:);

NozVFR1 = [VFRF0N VFRF30N VFRF40N VFRF50N VFRF70N VFRF80N];

OriVFR1 = [VFRF0O VFRF30O VFRF40O VFRF50O VFRF70O VFRF80O];

NozVFR=NozVFR1(1,:);

OriVFR=OriVFR1(1,:);

%% Plots

plot(NozVFR(1,:),NozP(1,:),'r*')

hold on

plot(OriVFR(1,:),OriP(1,:),'b+')

xlabel('Flowrate [m^3/s]')

ylabel('Change in Pressure [Pa]')

legend('Nozzle','Oriface')

title('Pressure V Flowrate')

[DGM]

Is this supposed to be using MFRF40N instead of MFRF30N?

REF40N(i+1) = 4*MFRF30N/(3.14159*AV*D1);

[DGM]

So it is supposed to be MFRF40N? Did that fix anything or change the behavior?

FWIW, I was only looking at the pattern of the code.

REF30N(i+1) = 4*MFRF30N/(3.14159*AV*D1);
...
REF40N(i+1) = 4*MFRF30N/(3.14159*AV*D1);
...
REF50N(i+1) = 4*MFRF50N/(3.14159*AV*D1);
...
REF70N(i+1) = 4*MFRF70N/(3.14159*AV*D1);
...
REF80N(i+1) = 4*MFRF80N/(3.14159*AV*D1);

If we're still stuck, you're going to have to find a way to see which variable/line number it's throwing the error at.

[Mathieu NOE]

hello Mason

maybe you should share also the data

[mason beal]

The main thing that confuses me is that it can run the line for MFRF30N with no problem, which has identical code to the next line. Yet it is still getting tripped up

[mason beal]

DGM i see what you were saying now about the repeated MFRF30N I apologize i did need to change that thank you. after changing it I am still getting the same error.

[mason beal]

I was able to figure it out.. The original while loop changed the i value to 8 so when the next tried to run it was stuck at 8. So I switched my variable to j then k etc. for the other loops. Thank you to everyone that helped I really appreciate it :).

[DGM]

Glad to hear it!

Answer 1

[Veronica Taurino]

Did you check your variable "i" has been set up to your desired value in the second while? Because in the first while you are updating it, so that the final value of ''i'' from the first "while" will be the input "i" for the second while.