2.5 Determination of diametrical sizes and numbers of hpt and lpt stages.

Number of HPT and LPT stages is determined by the formulas:

z_HPT=2у^*2L_HPT/[^*_tu_HPTm²]=2 ∙ 0.6²∙257717.711 / 0.905 / 436.697² =1.075 z_LPT = 2у^*2L_LPT/[^*_tu_LPTm²]= 2 ∙ 0.6² ∙193873.941 / 0.905 / 371.657² =1.12

Values of loading coefficient у^* is chosen in the range 0,55–0,65, efficiency ^*_t = 0.905, and values of angular velocities u_HPTm and u_LPTm are found:

u_HPTm = 411.25 ∙ 0.5543 / 0.522 = 436.697 (m/s)

u_LPTm = u_LPCD_3Hm/D_1lt = 350 ∙ 0.5543 / 0.522 = 371.657 (m/s)

Now we must round off obtained results to the integer numbers, hence, z_HPT = 1 and z_LPT = 1.

2.6. Determination of powers and frequencies of rotation of rotors in compressors and turbines.

Let’s find powers that are spent for LPC rotation N_LPC and HPC rotation N_HPC and powers that are produced by compressor high pressure turbine N_HPT and low pressure turbine N_LPT, frequencies of rotation of LPC п_LPC and HPC п_HPC and power turbine п_pt rotors:

N_LPC = G_airL_LPC = 27.724 ∙ 178980.827 = 4962064.448 (W);

N_HPC = G_airL_HPC = 27.724 ∙ 242150.53 = 6713381.294 (W);

N_HPT = G_тL_HPT = 26.049 ∙ 257717.711 = 6713288.654 (W);

N_LPT = G_тL_LPT = 26.049 ∙ 193873.941 = 5050222.289 (W);

(rpm) ;

(rpm) ;

(rpm) .

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