X7.731D}$@ {here is how I start the solution} eta_n=0.87 n=2 theta_1=20 Kv=0.97 {referring to figure 5.6} {Convert to SI units - use h and w as J/kg} pn=1000*101/14.7 Tn=(1000-32)/1.8 pa=101 hn=enthalpy(STEAM_NBS,p=pn,T=Tn) sn=entropy(STEAM_NBS,p=pn,T=Tn) ha=enthalpy(STEAM_NBS,p=pa,s=sn) hn-h1=eta_n*(hn-ha) {refer to figure 5-9} Vs1=(2*(hn-h1))^.5 Vb_opt=Vs1*cos(theta_1)/(2*n) Vb=Vb_opt theta_2=25 Vs1*sin(theta_1)=Vr1*sin(phi_1) {the axial component of absolute velocity is the same as that of relative velocity} Vs1*cos(theta_1)=Vr1*cos(phi_1)+Vb {tangential component of absolute velocity = tangential component of relative velocity + blade speed} gamma_1=phi_1 Vr2=Kv*Vr1 {and so on} {comments} {the axial component of absolute velocity is the same as that of relative velocity} {tangential component of absolute velocity = tangential component of relative velocity + blade speed} {note direction of blade rotation is positive} {the axial component of absolute velocity is the same as that of relative velocity} {tangential component of absolute velocity = tangential component of relative velocity + blade speed} {the axial component of absolute velocity is the same as that of relative velocity} {tangential component of absolute velocity = tangential component of relative velocity + blade speed} {note equation 5-27 in the text is incorrect, the second term in brackets should read (Vr2^2 - Vr1^2). I have used the simpler expression for energy transfer that we developed in class for the solution below, however the corrected expression in the book is equivalent} W_stage1=Vb*(Vs1*cos(theta_1)-Vs2*cos(delta_1)) {based on Euler equation from class Et = U*(Vu1-Vu2)} eta=(W_stage1+W_stage2)/(hn-ha) {$ID$ #223: Mechanical Engineering - University of Minnesota}(,hT5?hl7?6A_p? ?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs?OpDhȧOpDhȧs#p1g=ntablerows('&&&&&&&&&< ?OpDhȧOpDhȧs'T1NTABLEROWSs(L$)"< ?OpDhȧOpDhȧspn to SI units} {referriЎZ @?OpDhȧOpDhȧs(kPa1.8 pa=101 hn=enthalpy(stTn TNxToqq@?OpDhȧOpDhȧsC$4pa0PAxTo@?OpDhȧOpDhȧskPaabe?^BhnHNhxTo`H@?OpDhȧOpDhȧs)J/kggsteam_nbs,p=pn,T=Tn))sn&SNaxToJ5T @?OpDhȧOpDhȧsJ/kg-KKKX&8AP<=Cha !HAhxTo`p@?OpDhȧOpDhȧs)J/kggsteam_nbs,p=pa,s=sn))h1H1dxTo