Looping for a specified number of iteration

Question

SITI AISHAH 2019-10-6

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/483785-looping-for-a-specified-number-of-iteration

clc
clear all
%-------------------------------------------------------------------------%
% Specify the variable %
oil_SAE = 10; 
Temp_in = 85;          % Sump Temperature (°C)
d       = 0.15;        % Shaft Journal Diameter (Meter, m) 
r       = (d/2);       % Shaft Journal Radius (Meter, m)
N       = (166.69/60); % Shaft Speed (revolution per second,rps)
W       = 9000;        % Radial Load (Newton, N)
L       = 0.3;         % Bearing Length (Meter, m)
c       = 0.000026;     % Bearing clearance (Meter,m)
%-------------------------------------------------------------------------%
% Calculate the variable %
C_ratio     = r/c;        % Clearance ratio
P           = W/(d*L);    % Nominal Pressure (Pascal)
Slenderness = L/d  ;      % Bearing Aspect Ratio
%-------------------------------------------------------------------------%
% Viscosity - Temperature Chart
Temperature    = xlsread ('MFT','viscosity-temperature chart','A4:A30');
if oil_SAE     == 10
    V0          = 0.1089*10^(-3);
    b           = 1157.5 ;
elseif oil_SAE == 20
    V0          = 0.0937*10^(-3);
    b           = 1271.6;
elseif oil_SAE == 30
    V0          = 0.0971*10^(-3);
    b           = 1360.0;
elseif oil_SAE == 40
    V0          = 0.0827*10^(-3);
    b           = 1474.4;
elseif oil_SAE == 50
    V0          = 0.1171*10^(-3);
    b           = 1509.6;
elseif oil_SAE == 60
    V0          = 0.1288*10^(-3);
    b           = 1564.0;
end
%-------------------------------------------------------------------------%
% Calculation to find average temperature and viscosity %
Tf = Temp_in + 3;                  % Assumed Average Temperature (°C)
V  = V0*exp (b/((1.8*Tf)+127));    % Viscosity (Pa.s)
S  = (C_ratio)^2*((V*N)/P);        % Sommerfeld Number
if Slenderness      == 1
     delta_T        = (0.349109 + (6.00940*S)+(0.047467*(S^2)))*(P*(10^-6))/0.120;     % Temperature Rise(°C) at l/d=1
 elseif Slenderness == 1/2
     delta_T        = (0.394552 + (6.392527*S)-(0.036013*(S^2)))*(P*(10^-6))/0.120;    % Temperature Rise(°C) at l/d=1/2
 elseif Slenderness == 1/4
     delta_T        = 0.933828 + (6.437512*S)- (0.011048*(S^2))*(P*(10^-6))/0.120;     % Temperature Rise(°C) at l/d=1/4
else 
     delta_T        = ((33405*(S)^6)-(51557*(S)^5)+(30669*(S)^4)-(8871.9*(S)^3)+(1297.4*(S)^2)-(85.088*(S))+2.6111)*(P*(10^-6))/0.120; % Temperature Rise(°C) at l/d=Infinity
end
T_average  = Temp_in + (delta_T/2); % Average temperature (°C)
iter=0;
while iter <= 5 && abs (Tf-T_average)>0.001
    
    iter = iter + 1;
    delta = (Tf-T_average)/2;
    Tf    = Tf-delta;
    
    V  = V0*exp (b/((1.8*Tf)+127));   % Viscosity (Pa.s)
    S  = (C_ratio)^2*((V*N)/P);       % Sommerfeld Number
    
    if Slenderness  == 1
     delta_T        = (0.349109 + (6.00940*S)+(0.047467*(S^2)))*(P*(10^-6))/0.120;     % Temperature Rise(°C) at l/d=1
    elseif Slenderness == 1/2
     delta_T        = (0.394552 + (6.392527*S)-(0.036013*(S^2)))*(P*(10^-6))/0.120;    % Temperature Rise(°C) at l/d=1/2
    elseif Slenderness == 1/4
     delta_T        = 0.933828 + (6.437512*S)- (0.011048*(S^2))*(P*(10^-6))/0.120;     % Temperature Rise(°C) at l/d=1/4
    else 
     delta_T        = ((33405*(S)^6)-(51557*(S)^5)+(30669*(S)^4)-(8871.9*(S)^3)+(1297.4*(S)^2)-(85.088*(S))+2.6111)*(P*(10^-6))/0.120; % Temperature Rise(°C) at l/d=Infinity
end
    
    T_average  = Temp_in + (delta_T/2); % Average temperature (°C)
   
    disp ('Table for iteration');disp ('         c          Tf          V               S         deltaT        T average ');
    format shortG
    disp ([c',Tf', V',S',delta_T', T_average'])
    
end

** I want to loop the iteration as long as Tf-T_average is not in negative value and also not more than 0.001 which is 0 for 5th iteration. If the 5th iteration this is still not satisfied, then I want to increase the c where c=c+0.000001 for the next iteration until Tf-T_average=0. Please help me.Thanks