Investigation of Non-Axisymmetric Endwall Contouring in a Compressor Cascade

The current paper presents experimental and computational results to assess the effectiveness of non-axisymmetric endwall contouring in a compressor linear cascade. The endwaU was designed by an endwall design optimi- zation platform at 0° incidence （design condition）. The optimization method is based on a genetic algorithm. The design objective was to minimize the total pressure losses. The experiments were carried out in a compressor cascade at a low-speed test facility with a Mach number of 0.15. Four nominal inlet flow angles were chosen to test the performance of non-axisymmetric Contoured Endwall （CEW）. A five-hole pressure probe with a head diameter of 2 mm was used to traverse the downstream flow fields of the flat-endwall （FEW） and CEW cascades. Both the measured and predicted results indicated that the implementation of CEW results in smaller comer stall, and reduction of total pressure losses. The CEW gets 15.6% total pressure loss coefficient reduction at design condition, and 22.6% at off-design condition （＋7° incidence）. And the mechanism of the improvement of CEW based on both measured and calculated results is that the adverse pressure gradient （APG） has been reduced through the groove configuration near the leading edge （LE） of the suction surface （SS）.

Efficient Design of Multi-stage Cascade Waveband Separator

We propose a cascade system of filters for realizing a non-uniform waveband separation for optical networks. The use of such separation is required at the DEMUX stage in a optical OXC switching wavebands. The design of the system is based on optimized balanced tree, which minimizes the overall optical loss.

Cascading electron transfer and photophysics in a donor-π-acceptor graphene nanoconjugate

Electron-donating porphyrins(Por),electron-accepting phthalocyanines(Pcs),and reduced graphene oxide(RGO)were integrated into a multicomponent nanoconjugate(Por-RGO-Pc).The donor-π-acceptor nanoconjugate Por-RGO-Pc was characterized using Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM),scanning electron microscopy(SEM),atomic force microscopy(AFM),and ultraviolet-visible(UV-Vis)spectroscopy.Photoinduced cascading electron/charge transfer from Por to RGO and from RGO to Pc was established from fluorescence,electrochemical,and femtosecond transient absorption(fs-TA)spectroscopy studies.The increased distance between the electron donors and acceptors of the Por-RGO-Pc nanoconjugate compared to the parent materials and the intermediate RGO-Pc results in longlived charge separation,and an enhancement in nonlinear optical(NLO)absorption(a large NLO coefficient of about 827.44 cm/GW)towards nanosecond laser irradiation at 532 nm.