ここを参考に。
en.wikipedia.org
clear; close all; clc; % Input parameters D = 18e-2; %m L = 60e-2; %m R = D/2; x = linspace(0,L,20); % Tangent ogive rho = (R^2+L^2)/(2*R); y = sqrt(rho^2-(L-x).^2) + R - rho; subplot(331); plot(x,y,'k',x,-y,'k'); title('Tangent ogive'); % Conic y = x*R/L; subplot(332); plot(x,y,'k',x,-y,'k'); title('Conic'); % Bi-conic % mixing_rate1 = 0.35; % mixing_rate2 = 0.8; % L1 = mixing_rate1*L; % L2 = L-L1; % R2 = R; % R1 = mixing_rate2*R2; % y = zeros(size(x)); % for idx=1:length(x) % if x(idx) <=L1 % y(idx) = x(idx)*R1/L1; % else % y(idx) = R1+(x(idx)-L1)*(R2-R1)/L2; % end % end % subplot(332); % plot(x,y,'k',x,-y,'k'); % title('Bi-conic'); % Eliptical % y = R*sqrt(1-x.^2/L^2); % subplot(334); % plot(-x,y,'k',-x,-y,'k'); % title('Eliptical'); % Haack series theta = acos(1-2*x/L); C = 1/3; y = R/sqrt(pi)*sqrt(theta-sin(2*theta)/2+C*sin(theta).^3); subplot(333); plot(x,y,'k',x,-y,'k'); title('LV Haack'); C = 0; y = R/sqrt(pi)*sqrt(theta-sin(2*theta)/2+C*sin(theta).^3); subplot(334); plot(x,y,'k',x,-y,'k'); title('Von Kármán'); % Parabolic Kprime = 0; y = R*(2*(x/L)-Kprime*(x/L).^2)/(2-Kprime); subplot(335); plot(x,y,'k',x,-y,'k'); title('Parabola'); Kprime = 3/4; y = R*(2*(x/L)-Kprime*(x/L).^2)/(2-Kprime); subplot(336); plot(x,y,'k',x,-y,'k'); title('3/4 Parabolic'); Kprime = 1/2; y = R*(2*(x/L)-Kprime*(x/L).^2)/(2-Kprime); subplot(337); plot(x,y,'k',x,-y,'k'); title('1/2 Parabolic'); % Power series n = 3/4; y = R*(x/L).^n; subplot(338); plot(x,y,'k',x,-y,'k'); title('x^{3/4} Power'); n = 1/2; y = R*(x/L).^n; subplot(339); plot(x,y,'k',x,-y,'k'); title('x^{1/2} Power'); big;
実行結果
以下の空力データからは、Von Kármánか1/2 Powerが良いとのこと。
