D:\j_Iam_TEMP\_jh\_jh_ex2b_3a_v1.wxmx

Умова

Визначити силу гідростатичного тиску на бокову грань "MN" параболоїдального каналу висотою Hmn = 1 метр та шириною B = 3 метри. Рівень води у каналі H = 2 метри.
Аналітичні та чисельні розрахунки методом K123.
(%i1) kill(all);

\[\]\[\tag{%o0} \ensuremath{\mathrm{done}}\]

(%i1) load(draw)$
(%i7) ro:1000;g:9.81;H:2;B:3;Hmn:1;n:1000;

\[\]\[\tag{%o2} 1000\]

\[\]\[\tag{%o3} 9.81\]

\[\]\[\tag{%o4} 2\]

\[\]\[\tag{%o5} 3\]

\[\]\[\tag{%o6} 1\]

\[\]\[\tag{%o7} 1000\]

(%i12) fh(x):=x··2;fHab(x):=Hmn;fH(x):=H;Fx(h):=sqrt(h);diff(Fx(h),h);

\[\]\[\tag{%o8} \mathop{fh}(x)\mathop{:=}{{x}^{2}}\]

\[\]\[\tag{%o9} \mathop{fHab}(x)\mathop{:=}\ensuremath{\mathrm{Hmn}}\]

\[\]\[\tag{%o10} \mathop{fH}(x)\mathop{:=}H\]

\[\]\[\tag{%o11} \mathop{Fx}(h)\mathop{:=}\sqrt{h}\]

\[\]\[\tag{%o12} \frac{1}{2 \sqrt{h}}\]

(%i13) dh(h):=1/(2·sqrt(h));

\[\]\[\tag{%o13} \mathop{dh}(h)\mathop{:=}\frac{1}{2 \sqrt{h}}\]

(%i14) plot2d([fh(x),fHab(x),fH(x)],[x,0,2]);

\[\]\[\tag{%o14} false\]

Figure 1:D:\j_Iam_TEMP\_jh\_jh_ex2.png
Diagram
(%i15) plot2d(Fx(h),[h,0,H], [color,black],[style, [lines, 5,5]]);

\[\]\[\tag{%o15} false\]

Figure 2:
Diagram
(%i16) fp(h):=ro·g·(Hh);

\[\]\[\tag{%o16} \mathop{fp}(h)\mathop{:=}\ensuremath{\mathrm{ro}} g\, \left( H\mathop{-}h\right) \]

P_x - горизонтальна проекція сили тиску

(%i17) P_x:integrate(fp(h)·B,h,0,Hmn);

\[\]\[\tag{%o17} 44145.0\]

(%i18) mP_x:integrate(fp(h)·(Hh)·B·h,h,0,Hmn);

\[\]\[\tag{%o18} 26977.5\]

(%i19) mP_x_down:integrate(fp(h)·B·h,h,0,Hmn);

\[\]\[\tag{%o19} 19620.0\]

(%i20) h_D:mP_x/P_x;

\[\]\[\tag{%o20} 0.6111111111111112\]

(%i21) h_D_:mP_x_down/P_x;

\[\]\[\tag{%o21} 0.4444444444444444\]

(%i22) h_D+h_D_;

\[\]\[\tag{%o22} 1.0555555555555556\]

Figure 3:D:\j_Iam_TEMP\_jh\_jh_ex2_P_x.jpg
Diagram

P_x - чисельний алгоритм методу К123

(%i25) P_x_sum:0;dh:Hmn/n;h:0;

\[\]\[\tag{%o23} 0\]

\[\]\[\tag{%o24} \frac{1}{1000}\]

\[\]\[\tag{%o25} 0\]

(%i26) Pi_x(h):=ro·g·(Hh)·B;

\[\]\[\tag{%o26} \mathop{Pi\_ x}(h)\mathop{:=}\ensuremath{\mathrm{ro}} g\, \left( H\mathop{-}h\right) B\]

(%i28) for i:1 while h < Hmn do (Pi:Pi_x(h)·dh,P_x_sum:P_x_sum+Pi,h:h+dh);P_x_:P_x_sum;

\[\]\[\tag{%o27} \ensuremath{\mathrm{done}}\]

\[\]\[\tag{%o28} 44159.71499999999\]

(%i29) Px_test:integrate(Pi_x(hi),hi,0,Hmn);

\[\]\[\tag{%o29} 44145.0\]

(%i32) mP_x_sum:0;dh:Hmn/n;h:0;

\[\]\[\tag{%o30} 0\]

\[\]\[\tag{%o31} \frac{1}{1000}\]

\[\]\[\tag{%o32} 0\]

(%i34) for i:1 while h < Hmn do (Pi:Pi_x(h)·dh·h,mP_x_sum:mP_x_sum+Pi,h:h+dh);mP_x_:mP_x_sum;

\[\]\[\tag{%o33} \ensuremath{\mathrm{done}}\]

\[\]\[\tag{%o34} 19605.280095000024\]

(%i35) kill(h);

\[\]\[\tag{%o35} \ensuremath{\mathrm{done}}\]

(%i36) mPx_test:integrate(Pi_x(h)·(h),h,0,Hmn);

\[\]\[\tag{%o36} 19620.0\]

(%i38) h_D:mP_x_sum/P_x_sum;h_D_test:mPx_test/Px_test;

\[\]\[\tag{%o37} 0.44396301232922425\]

\[\]\[\tag{%o38} 0.4444444444444444\]

(%i39) Rel_ERROR:(100/h_D_test)·(h_D_testh_D),numer;

\[\]\[\tag{%o39} 0.10832222592453838\]

P_z - вертикальна проекція сили тиску

(%i40) kill(h);

\[\]\[\tag{%o40} \ensuremath{\mathrm{done}}\]

(%i45) ro:1000;g:9.81;H:2;B:3;Hmn:1;

\[\]\[\tag{%o41} 1000\]

\[\]\[\tag{%o42} 9.81\]

\[\]\[\tag{%o43} 2\]

\[\]\[\tag{%o44} 3\]

\[\]\[\tag{%o45} 1\]

(%i46) P_z:integrate(fp(h)·B·dh(h),h,0,Hmn);

\[\]\[\tag{%o46} 49050.0\]

(%i47) mP_z:integrate(fp(h)·B·dh(h)·(Fx(h)),h,0,Hmn);

\[\]\[\tag{%o47} 22072.5\]

(%i48) x_C:mP_z/P_z;

\[\]\[\tag{%o48} 0.45\]

Figure 4:D:\j_Iam_TEMP\_jh\_jh_ex2_P_z.jpg
Diagram

P_z - чисельний алгоритм методу К123

(%i53) ro:1000;g:9.81;H:2;B:3;Hmn:1;

\[\]\[\tag{%o49} 1000\]

\[\]\[\tag{%o50} 9.81\]

\[\]\[\tag{%o51} 2\]

\[\]\[\tag{%o52} 3\]

\[\]\[\tag{%o53} 1\]

(%i56) P_z_sum:0;dh:Hmn/n;h:0;

\[\]\[\tag{%o54} 0\]

\[\]\[\tag{%o55} \frac{1}{1000}\]

\[\]\[\tag{%o56} 0\]

coordinate - x {for h=i*dh x=sqrt(h)}
(%i58) fB(i,dh):=sqrt(i·dh); fB(1,dh),numer;

\[\]\[\tag{%o57} \mathop{fB}\left( i\mathop{,}\ensuremath{\mathrm{dh}}\right) \mathop{:=}\sqrt{i\, \ensuremath{\mathrm{dh}}}\]

\[\]\[\tag{%o58} 0.03162277660168379\]

(%i60) Pi_x(h):=ro·g·(Hh)·B; Pi_x(0.2);

\[\]\[\tag{%o59} \mathop{Pi\_ x}(h)\mathop{:=}\ensuremath{\mathrm{ro}} g\, \left( H\mathop{-}h\right) B\]

\[\]\[\tag{%o60} 52974.0\]

(%i62) fdb(i,dh):=(fB((i+1),dh)fB((i),dh))/dh;fdb(1000,dh),numer;

\[\]\[\tag{%o61} \mathop{fdb}\left( i\mathop{,}\ensuremath{\mathrm{dh}}\right) \mathop{:=}\frac{\mathop{fB}\left( i\mathop{+}1\mathop{,}\ensuremath{\mathrm{dh}}\right) \mathop{-}\mathop{fB}\left( i\mathop{,}\ensuremath{\mathrm{dh}}\right) }{\ensuremath{\mathrm{dh}}}\]

\[\]\[\tag{%o62} 0.4998750624609638\]

(%i63) for i: 0 while h < Hmn do (db:fdb(i,dh),Pi:Pi_x(h)·db·dh,P_z_sum:P_z_sum+Pi,h:h+dh)$
(%i65) P_z_:P_z_sum,numer;h;

\[\]\[\tag{%o64} 49064.52275520602\]

\[\]\[\tag{%o65} 1\]

FOR MOMENT P_z coordinate - x {for h=i*dh x=sqrt(h)}
(%i68) mP_z_sum:0;dh:Hmn/n;h:0;

\[\]\[\tag{%o66} 0\]

\[\]\[\tag{%o67} \frac{1}{1000}\]

\[\]\[\tag{%o68} 0\]

(%i69) for i: 0 while h < Hmn do (db:fdb(i,dh),Pi:Pi_x(h)·db·dh·fB(i,dh),mP_z_sum:mP_z_sum+Pi,h:h+dh)$
(%i71) mP_z_:mP_z_sum,numer;h;

\[\]\[\tag{%o70} 22003.335303355238\]

\[\]\[\tag{%o71} 1\]

(%i73) x_C_:mP_z_/P_z_,numer; x_C;

\[\]\[\tag{%o72} 0.44845713496765977\]

\[\]\[\tag{%o73} 0.45\]

(%i74) Rel_ERROR:(100/x_C)·(x_Cx_C_),numer;

\[\]\[\tag{%o74} 0.3428588960756102\]

P - Сила гідростатичного тиску

(%i76) P_x;P_z;

\[\]\[\tag{%o75} 44145.0\]

\[\]\[\tag{%o76} 49050.0\]

(%i77) P:sqrt(P_x··2+P_z··2);

\[\]\[\tag{%o77} 65990.02595089655\]

(%i78) phi_rad:atan(P_z/P_x),numer;

\[\]\[\tag{%o78} 0.83798122500839\]

(%i79) phi_grad:atan(P_z/P_x)·(180/%pi),numer;

\[\]\[\tag{%o79} 48.01278750418334\]

(%i80) d:tan(P_z/P_x);

\[\]\[\tag{%o80} 2.0199703317182265\]

(%i81) k:P_z/P_x;

\[\]\[\tag{%o81} 1.1111111111111112\]

Проекції вектора сили й координати (Projections of the force vector and coordinates)
(%i82) scale:100000;

\[\]\[\tag{%o82} 100000\]

(%i85) P_xv:P_x/scale;P_zv:P_z/scale;Pv:P/scale;

\[\]\[\tag{%o83} 0.44145\]

\[\]\[\tag{%o84} 0.4905\]

\[\]\[\tag{%o85} 0.6599002595089656\]

(%i86) kill(D);

\[\]\[\tag{%o86} \ensuremath{\mathrm{done}}\]

(%i90) h_D;x_C;phi_rad;k;

\[\]\[\tag{%o87} 0.44396301232922425\]

\[\]\[\tag{%o88} 0.45\]

\[\]\[\tag{%o89} 0.83798122500839\]

\[\]\[\tag{%o90} 1.1111111111111112\]

(%i91) eq:h_D=k·x_C+D;

\[\]\[\tag{%o91} 0.44396301232922425\mathop{=}D\mathop{-}0.5\]

(%i92) solve(eq,D);

\[\]\[rat: replaced 0.9439630123292242 by 2832833/3001000 = 0.9439630123292236\]

\[\]\[\tag{%o92} \left[ D\mathop{=}\frac{2832833}{3001000}\right] \]

(%i93) D:2832833/3001000,numer;

\[\]\[\tag{%o93} 0.9439630123292236\]

(%i94) y(x):=k·x+D;

\[\]\[\tag{%o94} \mathop{y}(x)\mathop{:=}\mathop{-}k x\mathop{+}D\]

(%i95) y(0.45);

\[\]\[\tag{%o95} 0.44396301232922364\]

(%i96) y1(x):=x··2;

\[\]\[\tag{%o96} \mathop{y1}(x)\mathop{:=}{{x}^{2}}\]

(%i97) eq1:k·x+D=x··2;

\[\]\[\tag{%o97} 0.9439630123292236\mathop{-}1.1111111111111112 x\mathop{=}{{x}^{2}}\]

(%i98) solutions:solve([eq1],[x]);

\[\]\[rat: replaced 0.9439630123292236 by 2832833/3001000 = 0.9439630123292236 \]\[rat: replaced -1.1111111111111112 by -10/9 = -1.1111111111111112\]

\[\]\[\tag{%o98} \]

(%i99) xvals: map(rhs, solutions);

\[\]\[\tag{%o99} \]

(%i100) x_coord:xvals[2],numer;

\[\]\[\tag{%o100} 0.5636428127589562\]

(%i101) h_coord:y1(x_coord);

\[\]\[\tag{%o101} 0.3176932203748278\]

(%i103) xx:x_coordP_xv;hh:h_coord+P_zv;

\[\]\[\tag{%o102} 0.12219281275895622\]

\[\]\[\tag{%o103} 0.8081932203748278\]

(%i104) plot2d([y1(x),y(x),[discrete,[x_coord],[h_coord]],
       [discrete,[x_coord,xx],[h_coord,hh]],
       [discrete,[x_coord,xx],[h_coord,h_coord]],
       [discrete,[x_coord,x_coord],[h_coord,hh]],
   [discrete,[0,2],[2,2]]],[x,0,2.1],[y,0,2.1],
   [style, [lines, 5,5], [lines, 3,1], [points, 5,2],[lines, 3,2],[lines, 3,2],[lines, 3,2],
       [lines, 3,1]]);

\[\]\[plot2d: some values will be clipped. \]\[plot2d: some values will be clipped.\]

\[\]\[\tag{%o104} false\]

Figure 5:
Diagram

Draw

--> /*  y = 1-1-4 */
(%i105) fv(y):=(20.25·y)/2;

\[\]\[\tag{%o105} \mathop{fv}(y)\mathop{:=}\frac{2\mathop{-}0.25 y}{2}\]

(%i126) draw2d(xrange = [1.1,4],
yrange = [0,2.5],
   font      = "Arial",
            font_size = 16,
title="Parabola",
   grid = true,
   proportional_axes=xy,
    /*   vertical W */
   fill_color = lightblue,
   Wall:polygon([[0,0],[0,2],[1,2],[1,1],[0.75,0.75··2],[0.5,0.5··2],[0.25,0.25··2],[0,0]]),
   W:polygon([[0,0],[0,2]]),
   W:polygon([[0.25,0.25··2],[0.25,2]]),
   W:polygon([[0.5,0.5··2],[0.5,2]]),
   W:polygon([[0.75,0.75··2],[0.75,2]]),
   W:polygon([[1,1··2],[1,2]]),
line_width=4,color=black,
explicit(y1(x),x,0,1.44),
   line_width=4,color=grey,
explicit(y1(x),x,1,sqrt(2)),
   color=red,line_width=1,
   explicit(y(x),x,0,x_coord),
   line_width=3,color=blue,
poly:polygon([[0,2],[sqrt(2),2]]),
   color=black,line_width=1,
   head_both = true,
   head_length = 0.2,
   head_angle = 10,
vector([2,2.2],[1,0]),
   label(["B",2.5,2.3]),
   points_joined = true,
   points([[2,2],[2,2.3]]),
   points([[3,2],[3,2.3]]),
   points([[3,2],[3.3,2]]),
   points([[3,0],[3,0.3]]),
   vector([3.3,0],[0,2]),
   points_joined = false,
   label_orientation = 'vertical,
label(["H",3.2,1]),
   label_orientation = 'horizontal,
   head_both = false,
   line_type = solid,
   head_length = 0.2,
head_angle = 5,
   color = black,
vector([x_C,(2.3)],[0,0.3]),
   label(["p_a",x_C+0.2,2+0.2]),
line_width=3,color=blue,line_type = dots,
poly:polygon([[0,1],[1,1]]),
color=black,point_type = filled_circle,point_size = 1.5,
points([[0,0],[1,1]]),
color=red,point_type = filled_circle,
points([[x_coord,h_coord],[x_C,h_D]]),
/*    color = red,
label(["Proection center pressure",x_C+0.7,h_coord]),
   color = navy,
label(["Horizontal proection vector (default)",x_C+1.3,h_D+0.1]), */
       color = black,
   label(["Px",x_C0.3,h_D+0.1]),
   label(["(0.56,0.31)",x_C+0.7,h_D0.1]),
/* label_orientation = 'vertical,
color = "#654321",
label(["Vertical orientation",x_C-0.2,h_D+0.6]), */
   label_orientation = 'vertical,
label(["Pz",x_C0.1,h_D+0.4]),
   line_type = solid,
   head_length = 0.2,
head_angle = 5,
   color = black,
   line_width=1.5,
vector([x_C,(h_D+P_zv)],[0,(P_zv)]),
vector([x_CP_xv,h_D],[P_xv,0]),
vector([(x_CP_xv),(h_D+P_zv)],[P_xv,P_zv]),
   color = black, fill_color = "#eeeeee",
rectangle([2,0],[3,2]),
   color = black,
    fill_color = "#cccccc",
   line_width=4,
rectangle([2,0],[3,1]),
   /* Epura  */
   line_width=1,color=blue,line_type = short_long_dashes,
   fill_color = "#ffffff",
poly:polygon([[00.1,0],[00.1,2],[10.1,0],[00.1,0]]),
   line_width=1,color=blue,line_type = solid,
   fill_color = lightblue,
poly:polygon([[00.1,0],[00.1,1],[0.50.1,1],[10.1,0],[00.1,0]]),
   /*   vertical W
   Wall:polygon([[0,0],[0,2],[1,2],[1,1],[0.75,0.75**2],[0.5,0.5**2],[0.25,0.25**2],[0,0]]),
   W:polygon([[0,0],[0,2]]),
   W:polygon([[0.25,0.25**2],[0.25,2]]),
   W:polygon([[0.5,0.5**2],[0.5,2]]),
   W:polygon([[0.75,0.75**2],[0.75,2]]),
   W:polygon([[1,1**2],[1,2]]),  */
   /*  Epura vectors */
line_type = solid,
   head_length = 0.3,
head_angle = 5,
   color = blue,
   line_width=3,
   vector([fv(0)0.05,0],[fv(0)0.05,0]),
   vector([fv(1)0.05,0.25],[fv(1)0.05,0]),
   vector([fv(2)0.05,0.5],[fv(2)0.05,0]),
   vector([fv(3)0.05,0.75],[fv(3)0.05,0]),
   vector([fv(4)0.05,1],[fv(4)0.05,0]),
       /*  GPL */
font      = "Arial",
            font_size = 16,
   color = "#0e406e",
label_orientation = 'vertical,
label(["www.k123.org.ua ",3.5,1.3]),
   label(["Kopanytsia Y (c)  2025",3.8,1.3])
)$
Figure 6:
Diagram
Figure 7:D:\j_Iam_TEMP\_jh\_jh_ex2b_3a_v1.svg
Diagram
(%i108) hh;h_D;

\[\]\[\tag{%o107} 0.8081932203748278\]

\[\]\[\tag{%o108} 0.44396301232922425\]

-----------------------------

Plot2d
(%i109) fh_D(x):=h_D_;

\[\]\[\tag{%o109} \mathop{fh\_ D}(x)\mathop{:=}\ensuremath{\mathrm{h\_ D\_ }}\]

(%i110) plot2d([fh(x),fHab(x),fH(x),fh_D(x),[discrete,[0.44,0.44],[0,1]],
       [discrete,[0.44],[0.45]],vector([0.44,0.45],[0,1])],[x,0,1.5],
   [legend, "parabola","Top_box", "Water", "P_x", "P_z", "point"],
   [style, [lines, 5,5], lines, [lines, 3,1], lines, lines, [points, 3,2]],
   [point_type, circle]);

\[\]\[plot2d: expression evaluates to non-numeric value everywhere in plotting range.\]

\[\]\[\tag{%o110} false\]

Figure 8:D:\j_Iam_TEMP\_jh\_jh_ex2c.png
Diagram
eq:y=x_C;plot2d([fh(x),fHab(x),fH(x),fh_D(x),eq],[x,0,2],[y,0,4]);

Answer

(%i116) P_x;P_z;P;h_D_;x_C;phi_grad;

\[\]\[\tag{%o111} 44145.0\]

\[\]\[\tag{%o112} 49050.0\]

\[\]\[\tag{%o113} 65990.02595089655\]

\[\]\[\tag{%o114} 0.4444444444444444\]

\[\]\[\tag{%o115} 0.45\]

\[\]\[\tag{%o116} 48.01278750418334\]

Figure 9:D:\j_Iam_TEMP\_jh\_jh_ex2.jpg
Diagram
Scale screen 300 px
(%i119) P_x/300;P_z/300;P/300;

\[\]\[\tag{%o117} 147.15\]

\[\]\[\tag{%o118} 163.5\]

\[\]\[\tag{%o119} 219.9667531696552\]

(%i120) P_:sqrt(P_x_··2+P_z_··2);

\[\]\[\tag{%o120} 66010.66445717201\]

REL_ERRORS

(%i121) Rel_ERROR_P_x:(100/P_x)·(P_xP_x_),numer;

\[\]\[\tag{%o121} \mathop{-}0.033333333333308936\]

(%i122) Rel_ERROR_mP_x_:(100/mP_x_down)·(mP_x_downmP_x_),numer;

\[\]\[\tag{%o122} 0.0750249999998791\]

(%i123) Rel_ERROR_mP_z:(100/mP_z)·(mP_zmP_z_),numer;

\[\]\[\tag{%o123} 0.31335234633486214\]

(%i124) Rel_ERROR_P_z:(100/P_z)·(P_zP_z_),numer;

\[\]\[\tag{%o124} \mathop{-}0.029608063620829527\]

(%i125) Rel_ERROR_P:(100/P)·(PP_),numer;

\[\]\[\tag{%o125} \mathop{-}0.031275190421675786\]


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