loop to calculate time using previous values

Question

Alina Abdikadyr 2023-3-31

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1938749-loop-to-calculate-time-using-previous-values

编辑： Dyuman Joshi 2023-4-4

Hello everyone!

Could you please help me with a code.

I have a loop and calculated time, so the values of time are the increments between the current and previous values. So how to generate the loop for the time where the previous ones can be added. For example, my first t values are 60.6664, 60.9712, 61.2792, 61.5902, 61.9045........ In the result of new time will be 60.9712, (60.9712+61.2792), (60.9712+61.2792+61.5902)......

W_takeoff = 10000;
W_landing=6000;
S = 20;
AR = 5;
cd0 = 0.02;
k = 1/pi/AR;
RC=0.51;
clalpha = 2*pi;
amin=2;
astall=12;
rho=1;
ct=0.001;
alpha_max=2.95;
cl_max=clalpha*alpha_max*pi/180;
cd_max = cd0 + k * cl_max * cl_max;
delta_w=50;
j=0;
  for w=W_takeoff:-delta_w:W_landing
      j=j+1;
      V(j) = sqrt(2*w/rho/S/cl_max); 
      D(j) = 0.5 * rho * V(j) * V(j) * S * cd_max;
      Thrust(j)=D(j); %for steady level flight condition
      F(j)=ct*Thrust(j); %fuel consumption
      Weight(j)=w;
      t(j)=delta_w/F(j);
      R(j)=V(j)*t(j);
  end 

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Answer 1

Dyuman Joshi 2023-3-31

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1938749-loop-to-calculate-time-using-previous-values#answer_1205884

编辑：Dyuman Joshi 2023-3-31

在 MATLAB Online 中打开

You can vectorize the loop -

W_takeoff = 10000;
W_landing = 6000;
S = 20;
AR = 5;
cd0 = 0.02;
k = 1/pi/AR;
RC=0.51;
clalpha = 2*pi;
amin=2;
astall=12;
rho=1;
ct=0.001;
alpha_max=2.95;
cl_max=clalpha*alpha_max*pi/180;
cd_max = cd0 + k * cl_max * cl_max;
delta_w=50;
j=0;
w=W_takeoff:-delta_w:W_landing;
V = (2*w/rho/S/cl_max).^(1/2);
D = 0.5*rho*V.^2*S*cd_max;
Thrust = D;
F = ct*Thrust;
Weight = w;
t = delta_w./F
t = 1×81
   60.6664   60.9712   61.2792   61.5902   61.9045   62.2219   62.5427   62.8667   63.1941   63.5250   63.8593   64.1972   64.5387   64.8838   65.2327   65.5853   65.9417   66.3020   66.6663   67.0347   67.4071   67.7837   68.1645   68.5496   68.9391   69.3330   69.7315   70.1345   70.5423   70.9548
R = V.*t;
%new time
T = cumsum(t)
T = 1×81
1.0e+03 *

    0.0607    0.1216    0.1829    0.2445    0.3064    0.3686    0.4312    0.4940    0.5572    0.6208    0.6846    0.7488    0.8134    0.8782    0.9435    1.0091    1.0750    1.1413    1.2080    1.2750    1.3424    1.4102    1.4784    1.5469    1.6158    1.6852    1.7549    1.8250    1.8956    1.9665