I. Source code

% % %69Type double30Mm clear all A=0.0737; % Cross-sectional area of gun (gun) bore A dm^2
G=0.354; % ammunition weight kg W0=0.22; % Chamber volume dm^3
l_g=19.54; % tube stroke DM P_0 =30000; % starting pressure30kpa
fai1=1.1947834; % degree of work coefficient K=1.02; % motion resistance coefficient φ1
theta =0.2; % Heat coefficient k of gunpowder- 1
f=950000; % Explosive power kg*dm/kg Nitrocellulose alpha=1; % residual gas molecular action correction dm^3/kg
delta=1.6; % Powder density γ kg/dm^3
ome=0.175; % The first dosage kg U1 =5.3752*10^- 5; % Burn rate coefficient of the first charge dm^3/(s*kg)
n1=0.85; The pressure index of the first charge n1 lambda=0.3311631; The shape characteristic of the first charge λ1
lambda_s=0.3685706; The shape characteristic of the splitting point of the first charge λ1s   0.3885706
chi=0.72347956; % the shape characteristic of the first charge was χ1
chi_s=1.4872194; % the split-point shape characteristic of the first charge was χ1s
mu=0.033166463; % The first charge shape characteristic μ1
et1=0.39*10^2 -; % The first charge is thick δ01, the burned thickness d1=0.38*10^2 -; % Inner diameter of the first charge d1 Ro1=0.1547; % drug type coefficient α1Lace type medicine granule % % % constant and the initial value calculation -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- l_0 = W0 / A; % Equal volume length l_0 Delta= OME /W0; Phi =K + ome/(3*G); % ignores the calculation coefficient of the secondary important work of the backseat motion energy v_j0=196*f*ome/(phi*theta*G);
v_j=sqrt(v_j0); % assume the limiting velocity B0 =98*(et1*A)^2/( u1*u1*f*ome*phi*G );
B=B0*(f*Delta)^(22 -*n1); % Z_s=1+Ro1*(d1/2+et1)/et1; % The radius of the tangential circle in the cross section of porous gunpowder during combustion and splitting, and the relative codependency of combustion when the particles are completely burned. psi_0=(1/Delta - 1/delta)/(f/P_0 + alpha - 1/delta); % Percentage of gunpowder burned, relative weight Z_0=(sqrt(1+4*psi_0*lambda/chi) - 1)/(2*lambda); % the burned out relative thickness of gunpowder z0 operator % % % solution -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - C = zeros (1.12);
C(1)=chi; C(2)=lambda; C(3)=lambda_s; C(4)=chi_s; C(5)=Z_s;
C(6)=theta; C(7)=B; C(8)=n1; C(9)=Delta; C(10)=delta; C(11)=alpha; C(12)=mu;
C;
y0=[Z_0;0;0; psi_0]; % Relative burning surface area L Projectile travel Projectile velocity Gunpowder burning percentage options = Odeset ('outputfcn'.'odeplot'); % integral parameter setting output function time trajectory graph [tt,y] = ode45(@ndd_fun,0:100,[Z_0;0;0],options,C); %4Order Runge Kutta function %% l = y(:,2); % Projectile travel l = l*l_0; fl = find(l>=l_g); fl = min(fl); [tt,y] = ode45(@ndd_fun,0:0.0001:fl,[Z_0;0;0],options,C);
 
Z = y(:,1);
lx = y(:,2); % projectile travel vx = y(:,3); % projectile velocity psi=(Z>=0&Z<1).*(chi*Z.*(1+lambda*Z+mu*Z.*Z))+(Z>=1&Z<Z_s).*((chi_s*Z).*(1+lambda_s*Z))+(Z>=Z_s)*1; % Gunpowder burning percentage L_psi =1-(Delta/delta)*(1-psi)-alpha*Delta*psi; px=(psi-vx.*vx )./(lx+l_psi); % Bore pressure format;Copy the code

Second, operation results

Third, note

Version: 2014 a