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The aerodynamic performance of axial compressor rotors is negatively affected by the ingestion of boundary layer fluids upstream. As the boundary layer becomes thicker, the blade tip load increases and the local loss is aggravated, especially under off-design operating conditions. The major objective of this research is to evaluate the potential for novel blade sweep designs that can tolerate the ingested low-momentum boundary layer fluids. An optimization design approach using a surrogate model and genetic algorithm is employed. By altering the blade stacking line, the optimized sweep design is obtained. The flow mechanisms that enable the performance of the compressor rotor to be improved are fully analyzed, and the findings indicate that the aerodynamic advantages primarily stem from two key aspects. First, in the tip region, the blade loads are decreased at various chordwise locations and the interaction of the tip leakage flow with the mainstream is alleviated. As a result, the loss near the tip is reduced. Second, the blade sweep design alters the distribution of shock intensity across the spanwise direction, leading to a decrease in shock wave intensity in the mid-span region. This is beneficial in reducing the shock wave/boundary layer interaction strength at the trailing edge of the blade airfoil. Overall, after the sweep design has been optimized to ingest the upstream boundary layer, the compressor rotor experiences a 0.8% improvement in adiabatic efficiency compared with the baseline rotor, while preserving the total pressure ratio and stall margin. Additionally, the redesigned compressor retains the overall performance level under clean inlet conditions. This research provides a potentially effective blade sweep optimization design strategy that allows transonic compressor rotors to tolerate low-momentum upstream boundary layer incoming flows.

To investigate the difference in the effect of ultrasound-guided puncture injection of polidocanol (PO) and ethanol (ET) in the treatment of renal and hepatic cysts (RHC), and to analyze the factors related to patients’ prognosis of disease recurrence.

A total of 105 patients with RHC admitted to our hospital from August 2020 to August 2021. Among them, 59 patients received ultrasound-guided puncture injection of ET (control group); the rest 46 received ultrasound-guided puncture injection of PO (observation grou). The success rate of one-time puncture and adverse reactions of the two groups were counted, and the levels of C-reactive protein (CRP), Cortisol (Cor), liver and kidney function. Patients were then followed up for a one-year prognosis, and the prognosis of RHC recurrence was recorded. Logistic regression analysis was performed to analyze the factors associated with the recurrence of cysts.

Postoperative CRP and Cor were observed to be lower than those in the control group, and hepatic and renal function was better than that in the control group (P<0.05). In addition, the incidence of adverse reactions was lower in the observation group than in group B (P<0.05). Cyst diameter, incomplete cyst aspiration, and post-sclerotic segregation were high-risk independent factors affecting prognostic cyst recurrence (P<0.05).

Ultrasound-guided injection of PO puncture sclerosis for RHC has excellent results. At the same time, patients need to be concerned about the diameter of the cyst, incomplete aspiration of the cystic fluid, and whether the cyst is separated after sclerosis.

This study reconstructed the flow field of a symmetrical variable inlet guide vane in a centrifugal compressor through the passive control method of vane slots. Based on the high-fidelity numerical simulation model verified by experiments, the influence of different slot forms on the flow field was investigated, and the passive control mechanism was revealed. The results demonstrated that the vane slot method can effectively suppress the suction surface separation and broaden the range of low-loss incidence angles. Overall, the 50_30 slotted vane achieves the best flow field control, with a 65.6% reduction in the total pressure loss coefficient and a 2.3° reduction in the deviation angle, respectively, at a 25° incidence angle. The linear characteristics of the pre-swirl grade variation curve with variable inlet guide vane incidence angles are also improved. Furthermore, changing the slot outlet angle has the most significant influence on the aerodynamic performance as it changes the throat width of the location, thereby affecting the flow rate and momentum of the jet. Finally, the impact of the velocity varies in the first self-similarity region on the slotted vane. The results indicate that, in contrast to the baseline vane, the suppression effect of the slot jet on the flow separation improves with the inlet velocity, whereas the deviation angle of the slotted vane declines with the inlet velocity. Meanwhile, the higher the incoming flow velocity, the better the slotted jet can inhibition of flow separation.