564 research outputs found

    Large scale optimization of transonic axial compressor rotor blades

    Get PDF
    [First Paragraphs] In the present work the Multipoint Approximation Method (MAM) by Toropov et al. (1993) has been applied to the shape optimization of an existing transonic compressor rotor (NASA rotor 37) as a benchmark case. Simulations were performed using the Rolls-Royce plc. PADRAM-HYDRA system (Shahpar and Lapworth 2003, Lapworth and Shahpar 2004) that includes the parameterization of the blade shape, meshing, CFD analysis, postprocessing, and objective/constraints evaluation. The parameterization approach adopted in this system is very flexible but can result in a large scale optimization problem. For this pilot study, a relatively coarse mesh has been used including around 470,000 nodes. The parameterization was done using 5 engineering blade parameters like axial movement of sections along the engine axis in mm (XCEN), circumferential movements of sections in degrees (DELT), solid body rotation of sections in degrees (SKEW), and leading/trailing edge recambering (LEM0/TEMO) in degrees. The design variables were specified using 6 control points at 0 % (hub), 20%, 40%, 60%, 80%, and 100% (tip) along the span. Thus the total number of independent design variables N was 30. B-spline interpolation was used through the control points to generate smooth design perturbations in the radial direction

    Automation grade increasing of mine drainage equipment when powered pumps from the soft starter

    Get PDF
    У статті розглядається доцільність застосування пристроїв плавного пуску асинхронних електродвигунів для систем шахтного водовідливу. Запропоновано алгоритм запуску нерегульованого насоса з використанням аналогового сигналу по струму статора для формування сигналу компенсації швидкості регульованого електродвигуна. Здійснено моделювання та зроблений порівняльний аналіз системи шахтного водовідливу зі стандартним алгоритмом пуску і при використанні сигналу компенсації по струму з подальшою обробкою сигналу в перетворювачі частоти в SoftPLC.In artich feasibility of soft starters for asynchronous motors mine drainage systems is considered. Starting algorithm for unregulated pump using an analog signal by the stator current signal, generated for speed compensation of regulated motor, is proposed. Implemented modeling and comparative analysis of mine drainage systems with a standard starting algorithm and with using of compensation signal by current with the subsequent processing of the signal in the frequency converter with the SoftPLC.В статье рассматривается целесообразность применения устройств плавного пуска асинхронных электродвигателей для систем шахтного водоотлива. Предложен алгоритм запуска нерегулируемого насоса с использованием аналогового сигнала по току статора для формирования сигнала компенсации скорости регулируемого электродвигателя. Осуществлено моделирование, произведен сравнительный анализ системы шахтного водоотлива со стандартным алгоритмом пуска и при использовании сигнала компенсации по току с последующей обработкой сигнала в преобразователе частоты в SoftPLC

    Miniature optical delay lines and buffers

    Get PDF
    Creation of miniature optical delay lines and buffers is one of the greatest challenges of the modern photonics which can revolutionize optical communications and computing. Several remarkable designs of slow light optical delay lines employing coupled ring resonators and photonic crystal waveguides has been suggested and experimentally demonstrated. However, the insertion loss of these devices is too large for their practical applications. Alternatively, the recently developed photonic fabrication platform, Surface Nanoscale Axial Photonics (SNAP) allows us to fabricate record small delay lines with unprecedentedly small dispersion and low loss. In this report, we review the recent progress in fabrication and design of miniature slow light devices and buffers, in particular, those based on the SNAP technology

    Sub-space approximations for MDO problems with disparate disciplinary variable dependence

    Get PDF
    The research leading to these results have been funded by the European Union Seventh Framework Programme FP7-PEOPLE-2012-ITN under grant agreement 316394, Aerospace Multidisciplinarity Enabling DEsign Optimization (AMEDEO) Marie Curie Initial Training Network
    corecore