Lean premixed prevaporized combustors with a centrally staged scheme are capable to reduce NOx emissions. Ignition is one of the key performances combustor. The present study proposes novel method improve ignition performance by using flow deflector. effects various deflector lengths and pressure drops on flame kernel propagation investigated in this work. It found that significantly improved process obtained high-speed camera under different operating conditions. timescale successful...

Due to the battery voltage performance of dual power supply open-winding permanent magnet synchronous motor (OW-PMSM) system in electric vehicles, dc bus voltages varies and traditional direct torque control (DTC) method will not be suitable may lead obvious ripples. Thus, this article, based on analysis effect vector variation, a ratio is employed switching table optimization strategy DTC for OW-PMSM, selection also modified according different ratio, then, optimized scheme OW-PMSM over...

Fuel injection and distribution play an important role in the formation migration of hot streaks gas turbine combustors determine exit temperature uniformity especially for modern low emission that have little or no primary dilution air flows. To better understand underlying mechanism evolution streak, both experimental numerical investigations been carried out a centrally staged tri-sector model combustor. Flow, spray, flame investigated by particle image velocimetry planar laser-induced...

In this paper, the transient ignition process of an annular combustor with 16 centrally staged swirling burners is experimentally investigated to study mechanism burner–burner flame propagation. The propagation patterns are studied by high-speed imaging. Three typical identified: kindled-swirling pattern, entrained-swirling and sweeping pattern. featured different paths motion. For fixed flow rates, motion mainly determined overall equivalence ratio Φ. Furthermore, during propagation, effect...

The ignition behaviors of an annular combustor consisting 16 centrally staged swirling burners are experimentally investigated in this work. This research is mainly focused on the light-round mechanism burner-burner flame propagation. flow structure burner and interaction between multiple well measured via particle image velocimetry method. Two high speed cameras applied to analyze process from side view top view. time, extinction limits, propagating pattern, dynamics leading point analyzed....

The ignition and flame propagation process within the centrally staged annular combustor is considerably intricate, particularly under low pressure conditions. Experiments with kerosene as fuel were conducted varying pressures ranging from 30 to 90 kPa. A high-speed camera was employed capture images of process. experiments illustrate that fuel–air ratio at boundary initially decreases then increases increasing drop different inlet pressures. a constant drop, exhibiting more pronounced...

Electronic systems with large stretchability have many applications. A precisely controlled buckling strategy to increase the has been demonstrated by combining lithographically patterned surface bonding chemistry and a process. The buckled geometry was assumed sinusoidal form, which may result in errors determine strains film. theoretical model is presented this letter study mechanics of type thin film/substrate system discarding assumption geometry. It shown that previous overestimates...

Nonreacting swirling flow behavior through a novel double swirl burner has been investigated in this paper using Detached Eddy Simulation (DES) calculations and experimental measurements. The effect of mixing both the inner jet (primary air or swirler) annular (secondary outer on structure analyzed. Moreover, pressure losses field characteristics have at different inlet mass rates combustor diameters. Due to drawbacks general loss predict drop high turbulence as well complex geometry,...

In this paper, an incorporated control strategy of both commutation and conduction torque ripples mitigation for brushless DC machine (BLDCM) with the sinusoidal back electromotive force(EMF) is proposed to reduce vibration noise household appliances higher comfortable capability. Based on combined ripple analysis respect stator flux linkage trajectory, a three-phase voltage vector injection (TVVI) method designed implemented in interval compensate sharp dips trajectory ripple, duty cycle...

A novel fault-tolerant inverter topology of the multiport dual-stator doubly salient electromagnetic machine (MDDSEM) drive is proposed in this paper for high reliability applications such as automotive and aerospace industries. The adopts four diverter switches to reconnect floating phase windings under fault conditions reconfigures dual be a five-leg inverter; output performance could maintained after single-phase open-circuit or short-circuit inverter. Compared with traditional method...

In this paper, an integrated motor-drive and battery-charging (IMB) system with a doubly salient electromagnetic machine (DSEM) is proposed to be implemented for electric vehicles. the driving mode, front-end dc/dc converter employed boost battery voltage improve speed range acceleration ability of DSEM. The field windings distribution 12/10-pole DSEM arranged constant self-inductance, adopted as inductance eliminate traditional filter excitation loss machine. charging could exploited...

Direct and indirect combustion noise sources co-exist in combustors. results from unsteady combustion. Indirect contributions are associated to entropy fluctuations convected through flow accelerating devices, such as a nozzle. Many analytical numerical studies on noises have been achieved since the late 1970s yet few experimental were carried out discriminate direct contributions. An method compute nozzle transfer functions separately has developed our previous work (Tao et al., 2013). It...

In this study, the compaction characteristics of recycled hot-mix asphalt (RHMA) were evaluated using void content (VV), energy index (CEI), slope accumulated (K), and lock point (LP). Then, effects parameters, including gradation RHMA, reclaimed pavement (RAP) content, temperature gyrations, number on RHMA investigated. An orthogonal experiment was designed data collected analyzed via range analysis; then, a regression model generated relying quadratic polynomial. Furthermore, used for...

For a long time, engine noise has been dominated by fan and jet noise. With their reduction for modern turbojets, instance, combustion is no longer negligible efforts are concentrated on its understanding. The objective of the European project RECORD to help understand fundamental mechanisms core noise, in order reduce it. In this paper, recent advances achieved within generated through nozzle presented. This work includes definition test bench at EM2C laboratory, equipped with various...

Abstract The exit temperature profile of an LPP combustor has been studied experimentally and numerically in this paper. designed to incorporate three sectors within which the flow, spray characteristics have investigated by PIV, PLIF thermocouple measurements. numerical simulation performed RANS method. Turbulences modeled realizable k-ϵ method combustion chemistry described FGM model. Liquid droplets tracked Lagrangian framework. discrete effusing cooling flows on flame tube source term...

Combustion is now considered as a non-negligible contributor to gas turbine noise. noise can be divided into two types: direct combustion directly caused by flame surface fluctuations and indirect non-homogeneities in the burnt gases, which radiate sound when interacting with first stages. The aim of present project obtain an extensive experimental database well better understanding physical phenomena inside pressurized chamber choked exhaust nozzle. To do so, model scale combustor has been...

Combustors are contributing to the core noise emission of aero-engines in terms direct and indirect combustion noise. The first is caused by unsteady heat release rate, second acceleration inflow inhomogeneities, such as entropy fluctuations, at combustor outlet or turbine. This work aims investigate generation mechanisms a choked laboratory scale combined experimental numerical study. Therefore, temperature fluctuations were determined experimentally well numerically cross-checked together...

Combustors running at lean conditions are prone to combustion instability. It occurs when the unsteady heat release interacts constructively with acoustic waves in combustor. Acoustic dampers such as perforated liners commonly used suppress instabilities. For analyzing damping effects of perforations on instability an annular chamber, a linear model has been developed this work. This comprises 1D straight injection ducts, 2D thin chamber and cavity that feeds flow through perforations. The...

This paper proposes a novel fault tolerant inverter topology for the high reliability of dual-stator doubly salient electro-magnet machine (DSEM), and thus maintaining undegraded output performance after open-circuit or short-circuit fault. The proposed adopts diverter switches to reconnect floating phase windings, reconfigures dual-inverter be five-leg inverter. operation principle optimized commutation method is analyzed eliminate unexpected current drop in order improve torque mode....