Novel Simplified Blade Hub Line Optimization of High-Pressure Ratio Centrifugal Compressor Design Using Numerical Simulations

Abstract

The focus of this research is to numerically investigate the effect of blade hub line variation on the performance (Total pressure-ratio and Isentropic-Efficiency) of centrifugal compressor from stall to choke to study the operating range and stall margin. An optimization technique is carried out in which the meridional profile hub line is modified and compared with the high Mach number SRV2 compressor designed and fabricated by DLR (German Aerospace Center). Numerical simulations showed significant increase in the stall margin and operating range by bargaining on pressure ratio and isentropic efficiency. Reynolds Averaged Navier Stokes (RANS) based k-ε model is used to predict turbulence using numerical simulations. The value of Y plus for the structured mesh near the boundaries is kept 35. Blade hub line being the important parameter, has substantial performance improvement of centrifugal compressor. The novel design improved the stall margin by 44 percent while operating range from stall to choke has been upgraded by 7.5 percent.

Performance prediction of centrifugal compressor based on a new volute loss model and corrected theoretical work

“…The convective fluxes are computed with a centered second‐order scheme with artificial dissipation of Jameson type, and the diffusive fluxes with a second‐order centered scheme. This algorithm strategy is adequate for a satisfying description of the impeller–diffuser interactions, according to what is usually reported in the literature 22 …”

“…This algorithm strategy is adequate for a satisfying description of the impeller-diffuser interactions, according to what is usually reported in the literature. 22 For the aerodynamic performance of the centrifugal compressor is simulated, the inlet method of total temperature and the total pressure is adopted, the temperature is 293.15 K, and the outlet mass flow is 1.33 kg/s. The reference pressure is set to 0 Pa and the energy equation is turned on.…”

“…The overall grid of the compressor is shown in Figure 7, and Figure 8 is the impeller single‐channel grid. The parameters to generate the mesh are derived from a previous study performed for the Centrifugal compressor with a similar structure 22 to ensure grid‐converged results.…”