Impact of inlet distortion on turbocharger compressor stage performance

Investigation on the casing static pressure distribution and stall behaviors in a centrifugal compressor with volute

The key element of this work is that it consists of experiments and simulations concerned with kernel characteristics, secondary plasma signal, IMEP performance, and combustion response, making use of MEHV (matching effect of high voltage) in order to increase thermodynamic combustion energy. This system, involving three plasma models, tanks, mixtures, mass flow controllers, regulators, coils, a high-speed camera and plugs, was designed by Labview software. The jet plasma model was verified as having characteristics increased greatly up to 39.8 kV of the surge voltage amplified by the transformer, from (-)0.11 ms to 0 ms and the jet plasma discharge was verified as having double characteristics increased to 32 kV primary and 8 kV secondary between 0 ms and 1 ms. Consequently, the IMEP performance analyzed by these experiments and simulations was notable in that it was demonstrated that the plasma energies could be promoted significantly and quickly to create a thermochemical reaction in the order of spark < arc < jet model in a chamber, and the plasma energies were shown to be predictable in that FCR (fuel consumption rate) could demonstrably be improved in a chamber.

Thermodynamic kernel, IMEP, and response based on three plasma energies

Reduced order model for unsteady aerodynamic performance of compressor cascade based on recursive RBF

Asymmetric structures of the bent inlet pipes and outlet volute are typically adopted in centrifugal compressors. By using asymmetric inlet/outlet structures, the uniformity of the compressor’s int...

https://journals.sagepub.com/doi/pdf/10.1177/0957650918774934

Casing wall static pressure distribution behavior in a centrifugal compressor with asymmetric inlet/outlet structures:

Numerical methods were carried out on a turbocharger compressor with inlet bent pipe to research a novel clocking effect between the inlet bend and the volute. It was found that the clocking effect with 3.4 percent of variations (1.9 percentage points) in compressor efficiency positively exists at the research point near chock. The reason for the changed efficiency loss is that the inlet bend induces a serious distortion of approaching flow to impeller inlet on one hand, and the downstream volute causes a circumferentially non-uniform distribution of pressure in vaneless diffuser. By adjusting the clocking positions between inlet bend and volute, not only is the unsteadiness of the flow rate through single impeller channel changed, but the uniformity of the incoming flow at the vaneless diffuser inlet is modulated as well. It is the dominant reason for the novel clocking effect that the bad uniformity causes more flow loss in both diffuser and volute.

Shan Chen

Papers

A novel clocking effect between inlet bend and volute in an automotive turbocharging system

Unsteady Flow Variability Driven by Rotor-stator Interaction at Rotor Exit