Supervisor:
Southwest Ordnance Industry Bureau
Organizer:
Chongqing Ordnance Industry Society
Chongqing University of Technology
Chongqing University of Technology
Multi objective aerodynamic optimization of a turbocharger turbine under off design condition
| DOI: | 10.11809/bqzbgcxb2025.01.018 |
| Keywords: | turbocharger turbine; radially fibred design; off design condition; multi objective aerodynamic optimization;entropy generation rate analysis |
| Abstract: | To improve the thermal performance of a vehicle special engine under variable operating conditions, a multi objective aerodynamic optimization was conducted for its turbocharger turbine based on radially fibred design under the off design operating condition. A multi objective optimization method of aerodynamic performance for the turbine is constructed using the single parameter analysis, the optimal Latin hypercube sampling method, the Kriging surrogate model and the gradient mutation hybrid optimization algorithm. This method has enhanced the isentropic efficiency and specific power of the turbine under off design condition without compromising the aerodynamic performance at design condition. The optimized turbine achieves an improvement of 2.03% in isentropic efficiency and 2.78% in specific power at the high expansion ratio operating point. By introducing the entropy generation theory and combining with the flow field analyses of the turbine, the mechanisms of improving aerodynamic performances are drawn as follows. The rotor inlet angle of attack decreases, the flow uniformity near the rotor trailing edge is improved, then the flow separations near the rotor inlet and the trailing edge are suppressed and the areas with high entropy generation rates are decreased, hence, the aerodynamic losses are reduced. The relative Mach number at the rotor outlet is reduced, the exit velocity loss is reduced, and then the isentropic efficiency is improved. The blade loading on the suction surface is reduced, the negative loading problem on the leading edge of the blade is alleviated, the overall torque of the rotor is increased, and then the specific power of the turbine is improved. This article provides useful references for the aerodynamic optimization and analysis of new flow mechanisms of turbocharger turbine under off design condition. |
| Issue: | Vol. 46 No. 1 (2025) |
| Published: | 2025-01-31 |