Application of TRIZ to develop an in-service diagnostic system for a synchronous belt transmission for automotive application

Development of robust diagnostic solutions to monitor the health of systems and components to ensure through life cost effectiveness is often technically difficult, requiring an effective integration of design development with research and innovation. This paper presents a structured application of TRIZ and USIT (Unified Structured Inventive Thinking) to generate concept solutions for an in-service diagnostic system for a synchronous belt drive system for an automotive application. The systematic exploration through TRIZ and USIT methods has led to the development of six concept solution ideas directed at the functional requirement to determine the state or condition of the belt. The paper demonstrates that the combined deployment of TRIZ and USIT frameworks is a valuable approach addressing difficult design problem

The influence of secondary flow structures in a turbocharger turbine housing in steady state and pulsating flow conditions

This paper presents a computational investigation into the effect of volute secondary flow structures on turbine inlet flow conditions. The steady state results show Dean type vortices exist early in the volute. As a result a substantial variation in absolute flow angle at the volute exit was observed. Pulsed flow simulations showed that the size and position of the secondary flow structures are time dependent. The resulting volute exit flow conditions were also found to be time dependent with the absolute flow angle at the volute exit varying with pulse pressure. This paper shows that that the secondary flow structures that exist in the volute as a result of cross sectional shape can have significant downstream effects on rotor performance

The introduction of a tilted volute design for operation with a mixed flow turbine for turbocharger applications

This paper introduces a tilted volute design for operation with a mixed flow turbine rotor. CFD results show an efficiency gain of up to 1.2% over the standard radial design at the highest tested turbine rotational speed. The efficiency gain was found to be the result of a reduction in separation from the blade suction surface. A reduction in the flow cone angle was also observed for the tilted housing, as a result an increase in negative incidence angles at the blade LE was observed. This work shows that optimization of the turbine housing specifically for mixed flow applications can yield significant performance benefits

The impact of housing features relative location on a turbocharger compressor flow

This work presents an investigation on a flow phenomenon marked by in-plane velocity non-uniformity associated with a ported shroud turbocharger compressor observed upstream of the compressor inlet at lower operating speeds. The effect of structural struts in the ported shroud (PS) cavity and the location of the volute tongue on velocity non-uniformity is studied in this paper by numerically modelling the complete compressor stage using a (Un)steady Reynolds Averaged Navier-Stokes (RANS & URANS) approach. The results show that the amplitude of in-plane velocity non-uniformity is reduced by removing the struts from the PS cavity. Furthermore, the change in location of the volute tongue is shown to either substantially diminish or enhance the amplitude of velocity non-uniformity based on the relative position of the volute tongue and the struts. The study concludes that the velocity non-uniformity is dependent on the coupled effect of volute tongue and the strut position in the PS cavity

A statistical approach to the analysis of surface pressure measurements on a pitching delta wing

No abstract available

Comparison of electromagnetic performance and power losses of a high-speed machine fed by PWM and PAM inverter strategies

This paper presents a comparative study of electromagnetic performance and power losses of a high-speed surface-mounted permanent magnet (SPM) machine supplied by a pulse-width modulation (PWM) and pulse-amplitude modulation (PAM), also known as quasi-square wave modulation (QSM). In the simulation the inverter is operated at different DC-bus voltage levels and different modulation indices, i.e. amplitude and frequency, for the PWM. The analysis is achieved using circuit simulation of the inverter linked with a 2D-finite element analysis (FEA) of the machine. The comparison focuses on the phase current and voltage, and distortion of the torque waveforms and the core, rotor and inverter losses. It is found that, at higher DC-bus voltage, higher phase current distortion is found and consequently higher torque ripple and induced harmonics in the rotor loss. Moreover, similar effect is found when higher amplitude modulation index is applied. Furthermore, higher frequency modulation index results in lower phase current harmonics and hence lower torque ripple and rotor loss however, this comes at the expense of the inverter loss

Ported shroud flow processes and their effect on turbocharger compressor operation

The ported shroud (PS) self-recirculating casing treatment is widely used to delay the onset of the surge by enhancing the aerodynamic stability of the turbocharger compressor. The increase in the stable operation region of the turbocharger compressor is achieved by recirculating the low momentum fluid that blocks the blade passage to the compressor inlet through a ported shroud cavity. While the ported shroud design delays surge, it comes with a small penalty in efficiency. This work presents an investigation of the flow processes associated with a ported shroud compressor and quantifies the effect of these flow mechanisms on the compressor operation. The full compressor stage is numerically modelled using a Reynolds Averaged Navier-Stokes (RANS) approach employing the shear stress transport (SST) turbulence model for steady state simulations at the design and near surge conditions. The wheel rotation is modelled using a multiple reference frame (MRF) approach. The results show that the flow exits the PS cavity at the near surge condition in the form of three jet-like structures of varying velocity amplitudes. Net entropy generation in the compressor model is used to assess the influence of the ported shroud design on the compressor losses, and the results indicate a small Inlet-PS mixing region is the primary source of entropy generation in the near surge conditions. The analysis also explores the trends of entropy generation at the design and the near surge condition across the different speed lines. The results show that the primary source of entropy generation is the impeller region for the design condition and the inlet-PS cavity region for the near surge condition