答案1
过去,我曾画过与你要求的类似的图。我的是一个有开口的圆圈,但它可能对你有用。
我使用参数图和一段 Matlab 代码来计算一些点和角度:
ang=35;
rs=0.7;
rb=2;
sep=0.6;
syms AX AY BX BY;
eq1=sqrt(AX^2+AY^2)==rs+rb;
eq2=sqrt(BX^2+BY^2)==rs+rb;
eq3=sqrt((AX-BX)^2+(AY-BY)^2)==2*rs+sep;
eq4=(AY+BY)/(AX+BX)==tand(ang);
[Ax,Ay,Bx,By]=solve(eq1,eq2,eq3,eq4,AX>0);
ax=double(Ax(1))
ay=double(Ay(1))
bx=double(Bx(1))
by=double(By(1))
anga=atand(ay/ax)
angb=atand(by/bx)
以及这个 tikz 代码:
\documentclass[margin=.1cm]{standalone}
\usepackage{tikz}
\usetikzlibrary{calc, intersections, arrows}
\begin{document}
\begin{tikzpicture}
% parameters
\def\rb{2}
\def\rs{0.7}
\def\ang{35}
\def\sep{0.6}
% matlab outputs
\def\ax{1.4808}
\def\ay{2.2577}
\def\bx{2.6280}
\def\by{0.6194}
\def\anga{56.7385}
\def\angb{13.2615}
% uncoment for help drawings
% \begin{scope} [help lines]
% \draw (-3,-3) grid (3,3);
% \draw (0,0) circle(\rb);
%
% \draw (\ax,\ay) circle (\rs);
% \draw (\bx,\by) circle (\rs);
%
% \draw (0,0) -- (\ax,\ay) -- (\bx,\by) -- cycle;
% \draw (0,0) -- (\ang:\rb*1.5);
%
% \end{scope}
\begin{scope}[red, very thick,samples=100]
\draw [domain=\anga:{360+\angb}] plot ({\rb*cos(\x)},{\rb*sin(\x)});
\draw [domain={90+\ang}:{180+\angb}] plot ({\bx+\rs*cos(\x)},{\by+\rs*sin(\x)});
\draw [domain={180+\anga}:{270+\ang}] plot ({\ax+\rs*cos(\x)},{\ay+\rs*sin(\x)});
\draw ({\ax+\rs*cos(270+\ang)},{\ay+\rs*sin(270+\ang)})
--++(\ang:\rs);
\draw ({\bx+\rs*cos(90+\ang)},{\by+\rs*sin(90+\ang)})
--++(\ang:\rs);
\end{scope}
\node[left, align=center, text width=1.5cm] at (0,0) {$V$\\{\tiny Volume of cavity}};
\node at (\ang:\rb) {$A$};
\node [align=center, text width=1.5cm] at (\bx,\by) {\tiny Area of opening};
\node [above,align=left] at (.2,\rb) {\tiny Length of \\\tiny opening port};
\draw [black!50!white,-latex,line width=.15cm] (\ang:\rb*0.8)--++(\ang:-1);
\draw [black!50!white,-latex,line width=.15cm] (\ang:\rb*1.4)--++(\ang:1);
\draw [latex-latex]
(\ax,\ay)++(90+\ang:-\rs/5)++ (\ang:-\rs)--++(\ang:2*\rs) node[midway,sloped, above]{$L$};
\draw [dashed, help lines]
(\ax,\ay)++(\ang:-\rs)--++(270+\ang:2*\rs+\sep)
(\ax,\ay)++(\ang:\rs)--++(270+\ang:2*\rs+\sep);
\end{tikzpicture}
\end{document}
这并不是您所要求的,但我希望它能有所帮助!
附言:
ang
是光圈的角度
rs
是小圆的半径
rb
是大圆的半径
sep
是开口的宽度