NOT GETTING PLOT , Actually i want a to find out the change in density,temp, pessure with altitude ( standard atmospheric properties). then use the density for other formula. plzz help . standard atmospheric prop. code given by friend,not understand

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function [rho,temp,press]=ceiling(h_in,toffset)
if nargin<2
toffset=0;
end
if nargin<1
h_in =0;
end
dimVarout=false;
if isa(h_in,'DimVar')
h_in=h_in/u.m;
dimVarout=true;
end
if isa(toffset,'dimVa')
toffset=toffset/u.k;
end
TonTi=1-2.255769564462953e-005*h_in;
press=101325*TonTi.^5.255879734954165;
temp=TonTi*288.15+toffset;
rho=press./temp/287.05287424707439;
if dimVarout
rho=rho*u.kg/(u.m^3);
temp=temp*u.k;
press=press*u.pa;
end
% formula
sigma=0.047193;
V_tip=180;
W=180;
Cd_avg=0.01;
R=2.235;
A=pi*R.^2;
P_e= 61147.4;
P_req=((W)^(3/2))./sqrt(2.*rho.*A)+(Cd_avg*rho*sigma*A.*(V_tip).^3)./(8) +747.643-(0.3*P_e);
V_c=(P_e-P_req)./W;
hold on;
plot(V_c,h_in,'b--');
xlabel("V_c");
ylabel("h_in");
plot(P_req,h_in,'r--');

Accepted Answer

KALYAN ACHARJYA
KALYAN ACHARJYA on 7 Mar 2021
Edited: KALYAN ACHARJYA on 7 Mar 2021
This is a function file, you need to pass the correct specific input values to get the output. Once I tried with a random array vector of the same size for h_in and tooffset, some curve is generated as below.
If you are a beginner in MATLAB, try it out. Here nargin is just checking number input argument enter to the functions. Refer the MATLAB Docs for more detail

More Answers (1)

Sourav singh
Sourav singh on 7 Mar 2021
function [rho,temp,press]=atmos(h_in,toffset)
if nargin<2
toffset=0;
end
if nargin<1
h_in =0;
end
dimVarout=false;
if isa(h_in,'DimVar')
h_in=h_in/u.m;
dimVarout=true;
end
if isa(toffset,'dimVa')
toffset=toffset/u.k;
end
TonTi=1-2.255769564462953e-005*h_in;
press=101325*TonTi.^5.255879734954165;
temp=TonTi*288.15+toffset;
rho=press./temp/287.05287424707439;
if dimVarout
rho=rho*u.kg/(u.m^3);
temp=temp*u.k;
press=press*u.pa;
end
% this is the function how should i call it .. i need the value of rho for my further formula
% this is my further formula how shuld i call the function so i can use rho
clc
clear
sigma=0.047193;
V_tip=180;
W=180;
Cd_avg=0.01;
R=2.235;
k=1.1;
A=pi*R.^2;
P_e= 61147.4;
P_req=k*((W)^(3/2))./sqrt(2.*rho.*A)+(Cd_avg*rho*sigma*A.*(V_tip).^3)./(8) +747.643-(0.3*P_e);
V_c=(P_e-P_req)./W;

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