> restart;#'therm_eq5.mws'.22-6-00.

Chapter 5: Set of pre-written equations available.

Balance equations for the evolution of a control mass

> eq5_1:=dm=0;eq5_2:=m*dv=F[A]*dt+m*g*dt;eq5_3:=m*de=dW+dQ;eq5_4:=m*ds=Int(1/T,Q)+S[gen];eq5_4a:=m*dphi=W[u]+Int(1-T0/T,Q)-T0*S[gen];

`:=`(eq5_1, dm = 0)

`:=`(eq5_2, `*`(m, `*`(dv)) = `+`(`*`(F[A], `*`(dt)), `*`(m, `*`(g, `*`(dt)))))

`:=`(eq5_3, `*`(m, `*`(de)) = `+`(dW, dQ))

`:=`(eq5_4, `*`(m, `*`(ds)) = `+`(Int(`/`(1, `*`(T)), Q), S[gen]))

`:=`(eq5_4a, `*`(m, `*`(dphi)) = `+`(W[u], Int(`+`(1, `-`(`/`(`*`(T0), `*`(T)))), Q), `-`(`*`(T0, `*`(S[gen])))))

Definition of total enthalpy

> eq5_11:=h[t]=h+e[m];

`:=`(eq5_11, h[t] = `+`(h, e[m]))

Balance equations for the evolution of a control volume

> eq5_14:=dm=Sum(dm[e],i=1..abert);eq5_15:=d(m*v)=F[A]*dt+m*g*dt-Sum(p[e]*A[e]*n[e]*dt,i=1..abert)+Sum(v[e]*dm[e],i=1..abert);eq5_16:=d(m*e)=dW+dQ+Sum(h[t,e]*dm[e],i=1..abert);eq5_17:=d(m*s)=Int(1/T,Q)+S[gen]+Sum(s[e]*dm[e],i=1..abert);eq5_18:=d(m*phi)=W[u]+Int(1-T0/T,Q)-T0*S[gen]+Sum((phi[e]+(p[e]-p0)/rho)*dm[e],i=1..abert);eq5_19:=d(m*phi)=W[u]+Int(1-T0/T,Q)-T0*S[gen]+Sum(psi[e]*dm[e],i=1..abert);

`:=`(eq5_14, dm = Sum(dm[e], i = 1 .. abert))

`:=`(eq5_15, d(`*`(m, `*`(v))) = `+`(`*`(F[A], `*`(dt)), `*`(m, `*`(g, `*`(dt))), `-`(Sum(`*`(p[e], `*`(A[e], `*`(n[e], `*`(dt)))), i = 1 .. abert)), Sum(`*`(v[e], `*`(dm[e])), i = 1 .. abert)))

`:=`(eq5_16, d(`*`(m, `*`(e))) = `+`(dW, dQ, Sum(`*`(h[t, e], `*`(dm[e])), i = 1 .. abert)))

`:=`(eq5_17, d(`*`(m, `*`(s))) = `+`(Int(`/`(1, `*`(T)), Q), S[gen], Sum(`*`(s[e], `*`(dm[e])), i = 1 .. abert)))

`:=`(eq5_18, d(`*`(m, `*`(phi))) = `+`(W[u], Int(`+`(1, `-`(`/`(`*`(T0), `*`(T)))), Q), `-`(`*`(T0, `*`(S[gen]))), Sum(`*`(`+`(phi[e], `/`(`*`(`+`(p[e], `-`(p0))), `*`(rho))), `*`(dm[e])), i = 1 .. ab...

`:=`(eq5_19, d(`*`(m, `*`(phi))) = `+`(W[u], Int(`+`(1, `-`(`/`(`*`(T0), `*`(T)))), Q), `-`(`*`(T0, `*`(S[gen]))), Sum(`*`(psi[e], `*`(dm[e])), i = 1 .. abert)))

Exergy flow and mass flow in a pipe

> eq5_19a:=psi=h[t]-T0*s;eq5_39:=m=rho*v*A;

`:=`(eq5_19a, psi = `+`(h[t], `-`(`*`(T0, `*`(s)))))

`:=`(eq5_39, m = `*`(rho, `*`(v, `*`(A))))

Balance equations for the steady evolution of a control volume

> eq5_39a:=0=Sum(rho*v*A,i=1..abert);eq5_39b:=0=F[A]+m*g-Sum(p*A*n,i=1..abert)+Sum(v*rho*v*A,i=1..abert);eq5_40:=0=W+Q+Sum(h[t]*rho*v*A,i=1..abert);eq5_41:=0=Int(1/T,Q)+S[gen]+Sum(s*rho*v*A,i=1..abert);eq5_41a:=0=W[u]+Int(1-T0/T,Q)-T0*S[gen]+Sum(psi*rho*v*A,i=1..abert);

`:=`(eq5_39a, 0 = Sum(`*`(rho, `*`(v, `*`(A))), i = 1 .. abert))

`:=`(eq5_39b, 0 = `+`(F[A], `*`(m, `*`(g)), `-`(Sum(`*`(p, `*`(A, `*`(n))), i = 1 .. abert)), Sum(`*`(`^`(v, 2), `*`(rho, `*`(A))), i = 1 .. abert)))

`:=`(eq5_40, 0 = `+`(W, Q, Sum(`*`(h[t], `*`(rho, `*`(v, `*`(A)))), i = 1 .. abert)))

`:=`(eq5_41, 0 = `+`(Int(`/`(1, `*`(T)), Q), S[gen], Sum(`*`(s, `*`(rho, `*`(v, `*`(A)))), i = 1 .. abert)))

`:=`(eq5_41a, 0 = `+`(W[u], Int(`+`(1, `-`(`/`(`*`(T0), `*`(T)))), Q), `-`(`*`(T0, `*`(S[gen]))), Sum(`*`(psi, `*`(rho, `*`(v, `*`(A)))), i = 1 .. abert)))

Energy balance for the steady evolution of a control volume with one input and one output

> eq5_43:=Dh[t]=w+q;eq5_43_1:=Qdot=mdot*c[p]*DT;

`:=`(eq5_43, Dh[t] = `+`(w, q))

`:=`(eq5_43_1, Qdot = `*`(mdot, `*`(c[p], `*`(DT))))

Exergy balance for the steady evolution of a control volume with one input and one output

> eq5_44:=Dpsi=w+Int(1-T0/T,q)-T0*s[gen];

`:=`(eq5_44, Dpsi = `+`(w, Int(`+`(1, `-`(`/`(`*`(T0), `*`(T)))), q), `-`(`*`(T0, `*`(s[gen])))))

Variation of exergy from input to output (steady)

> eq5_45:=Dpsi=Dh[t]-T0*Ds;

`:=`(eq5_45, Dpsi = `+`(Dh[t], `-`(`*`(T0, `*`(Ds)))))

Extended Bernoulli's equation (mechanical energy balance, steady, one input and one output)

> eq5_46:=w=Int(p,1/rho)+De[m]+e[mdf];eq5_47:=Wdot_id=mdot*Dp[t]/rho;

`:=`(eq5_46, w = `+`(Int(p, `/`(1, `*`(rho))), De[m], e[mdf]))

`:=`(eq5_47, Wdot_id = `/`(`*`(mdot, `*`(Dp[t])), `*`(rho)))

Total pressure for a perfect liquid

> eq5_55:=p[t]=p+(1/2)*rho*v^2+g*z;

`:=`(eq5_55, p[t] = `+`(p, `*`(`/`(1, 2), `*`(rho, `*`(`^`(v, 2)))), `*`(g, `*`(z))))

Total temperature for a perfect gas

> eq5_56:=T[t]/T=1+v^2/(2*c[p]*T);

`:=`(eq5_56, `/`(`*`(T[t]), `*`(T)) = `+`(1, `/`(`*`(`/`(1, 2), `*`(`^`(v, 2))), `*`(c[p], `*`(T)))))

Efficiency of an adiabatic compressor and an adiabatic expansor with the perfect gas model

> eq5_59:=eta=(pi[12]^((gamma-1)/gamma)-1)/(T2/T1-1);eq5_60:=eta=(1-T4/T3)/(1-(1/pi[12])^((gamma-1)/gamma));

`:=`(eq5_59, eta = `/`(`*`(`+`(`^`(pi[12], `/`(`*`(`+`(gamma, `-`(1))), `*`(gamma))), `-`(1))), `*`(`+`(`/`(`*`(T2), `*`(T1)), `-`(1)))))

`:=`(eq5_60, eta = `/`(`*`(`+`(1, `-`(`/`(`*`(T4), `*`(T3))))), `*`(`+`(1, `-`(`^`(`/`(1, `*`(pi[12])), `/`(`*`(`+`(gamma, `-`(1))), `*`(gamma))))))))

WARNING. A list of all variables follows, to copy and paste to the save command (after Maple7 there is no saving all). CAUTION: After pasting all, I must MANUALLY delete system variables: like RealRange_...

> sort([anames()]):

[eq5_1, eq5_11, eq5_14, eq5_15, eq5_16, eq5_17, eq5_18, eq5_19, eq5_19a, eq5_2, eq5_3, eq5_39, eq5_39a, eq5_39b, eq5_4, eq5_40, eq5_41, eq5_41a, eq5_43, eq5_43_1, eq5_44, eq5_45, eq5_46, eq5_47, eq5_4...
[eq5_1, eq5_11, eq5_14, eq5_15, eq5_16, eq5_17, eq5_18, eq5_19, eq5_19a, eq5_2, eq5_3, eq5_39, eq5_39a, eq5_39b, eq5_4, eq5_40, eq5_41, eq5_41a, eq5_43, eq5_43_1, eq5_44, eq5_45, eq5_46, eq5_47, eq5_4...
[eq5_1, eq5_11, eq5_14, eq5_15, eq5_16, eq5_17, eq5_18, eq5_19, eq5_19a, eq5_2, eq5_3, eq5_39, eq5_39a, eq5_39b, eq5_4, eq5_40, eq5_41, eq5_41a, eq5_43, eq5_43_1, eq5_44, eq5_45, eq5_46, eq5_47, eq5_4...

> save eq5_1, eq5_11, eq5_14, eq5_15, eq5_16, eq5_17, eq5_18, eq5_19, eq5_19a, eq5_2, eq5_3, eq5_39, eq5_39a, eq5_39b, eq5_4, eq5_40, eq5_41, eq5_41a, eq5_43, eq5_43_1, eq5_44, eq5_45, eq5_46, eq5_47, eq5_4a, eq5_55, eq5_56, eq5_59, eq5_60, "../therm_eq5.m":`

>