High Resolution RANS Nonlinear Harmonic Study of Stage 67 Tip Injection Physics

Numerical prediction of the Stage 67 transonic fan stage employing wall jet tip injection flow control and study of the physical mechanisms leading to stall suppression and stability enhancement afforded by endwall recirculation/injection is the focus of this paper. Reynolds averaged Navier–Stokes (RANS) computations were used to perform detailed analysis of the Stage 67 configuration experimentally tested at NASA's Glenn Research Center in 2004. Time varying predictions of the stage plus recirculation and injection flowpath were executed utilizing the nonlinear harmonic (NLH) approach. Significantly higher grid resolution per passage was achieved than what has been generally employed in prior reported numerical studies of spike stall phenomena in transonic compressors. This paper focuses on characterizing the physics of spike stall embryonic stage phenomena and the influence of tip injection, resulting in experimentally and numerically demonstrated stall suppression.

The Study on Harmonic of Photovoltaic Inverter Based on RTDS

Puts forward a kind of new harmonic study bases on photovoltaic merged into the distribution network through real-time simulation method: Build a model and control model in RTDS real time simulation system, by adding LCL filter, optimizing of filter parameters, analyzing harmonics of the data. At last analyzes the experimental results by using harmonic analysis module in MATLAB.

Waveform Measurement and Analysis of Common Household Appliances

Electricity power companies have the obligation to provide qualified electrical energy to the power user, the same as electricity customers, the power company claims to provide qualified energy, electricity customers are obliged to choose the right appliances to minimize the impact on the power quality of the power system . Higher harmonics is an important indicator of the impact of power quality, household appliances majority of non-linear loads, the use of the process will produce high harmonics, although the power is not, but a huge number, pooled together, will still PQ great impact. Therefore, the measurement of electrical waveforms common household appliances, will harmonic analysis, harmonic control, or other harmonic study is instructive.