基于低噪声的发动机冷却风扇的参数优化设计

本文对发动机冷却风扇的噪声产生机理进行了分析,介绍了风扇噪声影响因素及降噪策略。针对某型号为SVW7183的发动机冷却风扇,从影响风扇噪声性能诸因素中选取两种因素—叶片数、叶型安装角进行分析研究,总结出这两种因素对风扇噪声性能影响的规律性。根据上述研究结果并结合所研究风扇的实际工况,对原风扇结构与尺寸参数进行了优化设计。实验分析表明,优化后的风扇较原风扇性能有了显著提高。     

6月国内召回

1.东南（福建）汽车工业有限公司召回部分戈蓝汽车（1311辆） Who：东南汽车 Where：由于部分戈蓝水箱风扇的马达制造不良,马达工作温度偏高,极端情况下可能导致风扇叶片脱落,在此情况下如果车辆继续行驶．将导致发动机冷却能力不足，造成水温高问题．严重时发动机损坏．车辆熄火。     

试验设计在汽车冷却风扇安全性中的应用

早期汽车的冷却风扇是用发动机驱动的机械风扇,起着冷却发动机的作用。随着技术发展,机械风扇逐渐被电动风扇替代,致使发动机需要更加智能化的风扇。通过发动机电子控制单元,根据设计要求使风扇的开启与速度匹配,风扇不仅起到了冷却发动机的作用,而且可以使发动机运行     

国内召回 东南（福建）汽车

病例 东南（福建）汽车工业有限公司从2010年6月1日起,召回部分2008款戈蓝汽车1311辆。 涉及原因为,水箱的风扇电机制造不良,在长时间工作后会出现电机工作温度偏高,极端情况下可能导致风扇叶片脱落,在此情况下如果车辆继续行驶．将导致发动机冷却能力不足．严重时发动机损坏．车辆熄火。     

浅谈无叶风扇的原理应用工业前景

英国著名发明家詹姆士.戴森的全新发明无叶风扇,又可称作"戴森空气增加器",可产生神奇的凉风,但是由于没有叶片,因此不会覆盖灰尘,使用便捷、安全。本文结合无叶风扇的原理,对其在工业中的应用进行分析与阐述。     

逆向工程技术在风扇叶片模具设计的应用

本研究运用逆向工程技术,对风扇叶片进行模型重建并完成其成型工艺与模具设计。风扇叶片外形曲面比较复杂,采用逆向工程方法,利用三维扫描仪表面点云数据采集工作。应用Geomagic和UG软件进行点云数据处理、曲面重构和模型重建,然后用UG软件中Mold Wizard模块完成该产品的成型工艺与模具设计。     

重要国际标准介绍（80）

重要国际标准介绍（８０）风扇标准，ＩＳＯ／ＴＣ１１７送来的一股清风生活中常见的风扇在庞大的风扇家族中，仅仅是一个微不足道的部分。对风扇有这样一个普遍的技术定义：“风扇是一种带有旋转叶片的装置，该装置接收机械能，并利用扇叶的运动维持气体通过叶片持续流动...     

五十铃汽车硅油风扇离合器

<正> 一种轻型汽车的节能装置一五十铃汽车硅油风扇离合器,由黄岩市宏达汽车配件厂试制成功,最近通过鉴定。 这种汽车硅油风扇离合器以硅油为扭矩传递的介质,风扇可根据发动机的热负荷来自动控制工作。当发动机水温高于某一温度     

基于FLUENT的风扇CFD模拟仿真研究

利用CFD技术对发动机冷却风扇气动性能进行数值模拟仿真计算对提高冷却风扇的性能以及提高设计效率具有重要的意义。文章利用FLUENT软件对冷却风扇进行CFD模拟计算。首先。利用Solidworks软件建立风扇三维实体模型;其次.在软件GAMBIT中,根据风扇的边界条件建立仿真模型,包括旋转流体区、管道区、进口区和出口区,并对其进行网格划分;再次,在FLLYENT中设置具体的边界条件,进行模拟仿真计算,得到风道内速度场、压力场分布云图;最后,将质量流速的仿真结果与MATLAB软件的计算结果进行对比,验证了仿真结果的可靠性。     

发动机叶片易损部位的应力计算分析

建立了某发动机压气机叶片的三维有限元模型,对其进行了应力场分析,研究叶片的振动危险点主要分布情况,为下一步对叶片进行静频、相对振动应力分布测试以及通过危险点表面状态测试预测叶片剩余寿命提供技术依据。     

Incumplimiento del salario mínimo en Europa central y oriental

En este estudio se analiza el incumplimiento del salario mínimo durante el periodo 2003–2012 en diez países de Europa central y oriental con salario mínimo obligatorio nacional. A partir de los datos de EU‐SILC y la metodología propuesta por Bhorat, Kanbur y Mayet (2013), se cuantifica la incidencia y magnitud del incumplimiento. Se realizan análisis de regresión sobre determinantes individuales, laborales y macroeconómicos. Aunque la incidencia permanece relativamente baja, los trabajadores a los que se dirigen las políticas de salario mínimo parecen los más expuestos a su incumplimiento. Con el tiempo, una mayor incidencia se asocia a una razón más alta entre salario mínimo y salario medio.     

Cultural Economy Planning in Creative Cities: Discourse and Practice

While a growing body of research analyses the functional mechanisms of the cultural or creative economy, there has been little attention devoted to understanding how local governments translate this work into policy. Moreover, research in this vein focuses predominately on Richard Florida's creative class thesis rather than considering the wider body of work that may influence policy. This article seeks to develop a deeper understanding of how municipalities conceptualize and plan for the cultural economy through the lens of two cities held up as model ‘creative cities’ — Austin, Texas and Toronto, Ontario. The work pays particular attention to how the cities adopt and adapt leading theories, strategies and discourses of the cultural economy. While policy documents indicate that the cities embrace the creative city model, in practice agencies tend to adapt conventional economic development strategies for cultural economy activity and appropriate the language of the creative city for multiple purposes.     

Input/output ranges and performance: an examination of US machine tool producers

Despite the establishment of high-tech multinational enterprises (MNEs) in Ireland since the late 1950s, the country did not succeed in closing the technological gap with most of its EU counterparts. The weak National System of Innovation (NSI), and in particular low business and government R&D levels, combined with a lack of research and technology linkages between MNEs and indigenous firms, explain these poor results. However, the Shannon region in the West of the country presents some specific institutional characteristics that could theoretically make the region a strong technological enclave. The various actors in the region - i.e. the administrative, financial, political and research institutions, as well as the business organizations - have indeed infused a new type of economic development. After a brief review of the available concepts and models articulated around these actors and their interrelationships, the paper analyses whether the Shannon region, taken as an illustrative example, mirrors a specific economic and technological localized setting. The study is based on a survey of indigenous and foreign firms.     

Sixty years of discrimination and diversity research in human resource management: A review with suggestions for future research directions

This article reviews discrimination and diversity research published in Human Resource Management (HRM) over the past 60 years. While discrimination and diversity are very different constructs, it is often informative to study them together, because when people recognize each other's diversity, this can result in bias, stereotyping, and discrimination. We conducted bibliographic searches for terms related to discrimination and diversity as well as a manual search through every title and abstract published in HRM over the last 60 years to assess article relevance. The search resulted in 135 research articles with 136 unique studies (i.e., samples) which are reviewed in this article. Sex and race are the demographics that have been examined the most in HRM, while religion has been examined the least. Moreover, the number of studies examining lesbian, gay, bisexual, transgender, and queer (LGBTQ) employees in the workplace in HRM has grown quickly within the past 10 years, culminating in a recent meta‐analysis. Our review looks at some of the earliest research published, the most recent research published, and the overall trends we identified in the research over the years for both discrimination and diversity articles. We then make future research suggestions and recommendations to advance the study of discrimination and diversity in the coming years.     

The Early History of the Cumulants and the Gram-Charlier Series

The early history of the Gram-Charlier series is discussed from three points of view: (1) a generalization of Laplace's central limit theorem, (2) a least squares approximation to a continuous function by means of Chebyshev-Hermite polynomials, (3) a generalization of Gauss's normal distribution to a system of skew distributions. Thiele defined the cumulants in terms of the moments, first by a recursion formula and later by an expansion of the logarithm of the moment generating function. He devised a differential operator which adjusts any cumulant to a desired value. His little known 1899 paper in Danish on the properties of the cumulants is translated into English in the Appendix.     

Capturing the Implications of Services Trade Liberalization

This paper evaluates the impact of service sector trade liberalization on the world economy by a ten-region, eleven-sector CGE model with import embodied technology transfer from developed countries to developing countries. Simulation results show that service sector trade liberalization not only directly affects world service production and trade, but also has significant implications for other sectors in the economy. The major channel of the impact is through inter-industry input-output relations and TFP growth induced from services imported by developing countries from developed countries, which may be embodied with new information and advanced technology.     

City Children and Genderfied Neighbourhoods: The New Generation as Urban Regeneration Strategy

Former industrial cities in the West are employing gentrification as urban policy. In these policies, women and families currently play an important role as gentrification pioneers. In my analysis of Rotterdam in the Netherlands, I propose the term genderfication to understand the gender dimensions of this process. Genderfication refers to the production of space for different gender relations. I analyse Rotterdam's urban planning program for becoming a ‘child‐friendly city’, which entails replacing existing urban dwellings with new, larger and more expensive ‘family‐friendly homes’ as a strategy for urban re‐generation. Urban re‐generation supplements regeneration in the form of material and economic restructuring, and refers to the replacement of part of the current population by a new and better suited generation. The ‘child‐friendly city program’ is considered in tandem with punitive ‘youth policies’.     

Hierarchical Models in Environmental Science

Environmental systems are complicated. They include very intricate spatio-temporal processes, interacting on a wide variety of scales. There is increasingly vast amounts of data for such processes from geographical information systems, remote sensing platforms, monitoring networks, and computer models. In addition, often there is a great variety of scientific knowledge available for such systems, from partial differential equations based on first principles to panel surveys. It is argued that it is not generally adequate to consider such processes from a joint perspective. Instead, the processes often must be considered as a coherently linked system of conditional models. This paper provides a brief overview of hierarchical approaches applied to environmental processes. The key elements of such models can be considered in three general stages, the data stage, process stage, and parameter stage. In each stage, complicated dependence structure is mitigated by conditioning. For example, the data stage can incorporate measurement errors as well as multiple datasets with varying supports. The process and parameter stages can allow spatial and spatio-temporal processes as well as the direct inclusion of scientific knowledge. The paper concludes with a discussion of some outstanding problems in hierarchical modelling of environmental systems, including the need for new collaboration approaches.     

Multinomial distributions applied to random sampling of particulate materials

When sampling a batch consisting of particulate material, the distribution of a sample estimator can be characterized using knowledge about the sample drawing process. With Bernoulli sampling, the number of particles in the sample is binomially distributed. Because this is rarely realized in practice, we propose a sampling design in which the possible samples have a nearly equal mass. Expected values and variances of the sample estimator are calculated. It is shown that the sample estimator becomes identical to the Horvitz–Thompson estimator in the case of a large batch-to-sample mass ratio and a large sample mass. Simulations and experiments were performed to test the theory. Simulations confirm that the round-off error due to the discrete nature of particles is negligible for large sample sizes. Sampling experiments were carried out with a mixture of PolyPropylene (PP) and PolyTetraFluorEthylene (PTFE) spheres suspended in a viscous medium. The measured and theoretical variations are in good agreement.