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CFD 해석을 통한 변속기 시스템 성능 향상 방안
변속기 시스템은 엔진에서 바퀴로 동력을 전달하기 위한 기어, 베어링 샤프트 등의 부품들로 구성됩니다. 각 구성품들은 운전에 의한 마찰로 발생된 열로 인해 손상되거나 열화 될 수 있습니다. 또한 운전 시 사용되는 오일량이 줄어들 경우 처닝로스가 발생되며 이는 시스템 과열의 잠재적 원인이 되기도 합니다. CFD 해석은 변속기 시스템의 이러한 열에 의해 발생되는 손실을 최소화 하며 성능을 극대화 하기 위한 조건을 구현하는데 이용할 수 있습니다. 또한 변속기 내부의 유동 현상을 예측하며 이를 개선하는데 있어서 시험을 통해 찾기는 매우 어려우며 CFD 해석은 공기와 오일 간의 혼합 정도를 도출하여 최적의 유동 패턴을 찾아내어 시스템의 윤활 성능을 개선시키는데 사용할 수 있습니다. 최근 개발된 다상체적법(VOF)과 중첩 격자(Overset Grids) 기법을 변속기 시스템 해석에 적용함으로써 기어의 움직임을 보다 쉽게 묘사 할 수 있으며 기어와 유체간의 상호작용을 안정적으로 모델링 할 수 있습니다. 이번 동영상에서는 변속기 시스템의 오일 유동과 기어의 작동을 묘사하기 위해 사용된 CFD 해석 기법을 소개합니다.
Charts are important - they play a primary role in decision-making when it comes to evaluating CFD results. Have you ever counted how often you change a chart after you’ve first created it? I’ll speculate it’s more than you think… you’ll probably want to change line and symbol colors and styles, change the range on both axes, change the fonts, and then change the colors again… these picks and clicks and scrolls take time. If you are using Excel or Matlab to create your charts, you lose the implicit connection between the chart and the data sources within your .sim file - going back and forth between the two costs you more time. Worse still, if you’re used to a certain plotting package, there are differences compared to STAR-CCM+® on where in the UI you need to make those changes. In having to switch back and forth between plotting packages, the time spent looking for where you need to make a change is potentially greater than the time needed to actually make it. To understand and communicate the information your charts contain more quickly, and to make your finalized charts faster in STAR-CCM+, version 12.02 introduces Chart Highlighting.
Software development is sometimes similar to raising a child. After the excitement of a new arrival with tentative steps and the promise of great things in the future, it develops into a moody teenager, usually working well but prone to tantrums. The final stage for both children and software is a graduation to a responsible adult, working well, providing benefits, and giving great results. Has EHP finally taken the last step and matured? Has the prodigy child finally turned into a responsible adult? Ever since its inception and first tentative steps in the market as an add-on, we at Siemens PLM and our clients have had to live with its tantrums and acts of genuine helpfulness. The teenage years were particularly difficult, not wanting to move on from version 9.06 while its big brother STAR-CCM+® went seamlessly through its three releases per year gears.
Optimize the performance of SCR systems through simulations
Selective Catalytic Reduction (SCR) is widely used within industry to help meet the challenging Nitric Oxide (NOx) emission requirements for diesel engines. There are a number of important criteria necessary for designing an efficient SCR system, including fast mixing of the urea-water spray with the exhaust gases and high ammonia uniformity at the SCR device. However, one problem that threatens the life and performance of the system is solid urea deposit formations. The deposits can generate backpressure and material deterioration, causing decreases in both engine and emission performance of...
강제 및 자연 대류 냉각 시뮬레이션
전자 장치에서 가장 일반적인 두 가지 냉각 방법은 강제 및 자연 대류 냉각입니다. 자연 대류는 고유의 신뢰성 때문에 종종 이상적으로 여겨지지만 열 방출 능력에는 한계가 있습니다. 강제 대류 접근법은 팬과 같은 추가적인 장애 지점이 생겨나지만, 열 방출이 상당하게 증가된다면 추가적인 위험은 수용 될 수 있습니다. 열해석 시뮬레이션은 설계 엔지니어가 시스템의 세부 설계를 도와 사용 가능한 냉각 방식을 평가하는데 사용되는 핵심 도구입니다. 이 동영상에서는 STAR-CCM+®를 사용해 강제 및 자연 대류 시뮬레이션을 수행하는 모범 사례에 대해 설명합니다. 열해석 담당 엔지니어가 시뮬레이션을 효과적으로 사용하여 신뢰할 수 있는 시스템에 대해 설계의 어려운 작업을 도울 수 있도록 보다 자세한 시뮬레이션 단계와 기본적인 크기 조정 계산을 다룹니다.
If you haven’t had your head under a rock lately, you’ve seen the headlines. Here, let me get you fully up to speed on the latest: Diesel recall: which cars are affected, will my MPG decrease, and should I still buy a diesel? Volkswagen reaches deal for remaining 80,000 Dieselgate vehicles FCA accused by EPA of failing to disclose software allowing excess diesel emissions Now I’m not here to postulate the hows and whys any given manufacturer has chosen to use any so-called “defeat devices” or point any fingers of blame, but I will speculate that the diesel engine isn’t doomed or disappearing anytime soon. While I personally prefer the sound and response of an old-fashioned, naturally aspirated gasoline V8, Rudolf Diesel definitely invented the workhorse of the IC engine world back in the late 1800s and it’s hard to not appreciate it for what it is. Its prevalence globally in passenger cars is significant, but it’s even more prolific when you look at how many are used for on-highway medium and heavy-duty trucking applications, off-highway usage, marine, industrial, etc. It’s everywhere! So we currently face some very difficult challenges to reduce harmful emissions within required limits with governments worldwide constantly tightening those limits. It’s a very difficult problem to address, but it’s not in our nature to just back down from difficult problems, pack up our toys and go home! We engineers want to help solve those difficult problems, don’t we! In the long term, that may mean finding a suitable replacement for the IC engine (there’s plenty of activity in this area right now and, undoubtedly, more coming), but in the short term this means working smarter with better tools to reduce the output of harmful emissions, improve the performance (power) and efficiency (fuel economy), reduce the size/weight and reduce the cost of the diesel engine.
While most readers may not remember their bath time as a child, you may have a little one who enjoys it every day. I love seeing my little one’s curiosity when playing with the bubbles, asking questions such as “How are bubbles formed?” and, “Why are some bubbles small and others large?” There may also be an “ooh” moment: “Look how those bubbles have stuck together to become one.” The engineering term for getting together is, of course, coalescence. Coalescence and breakup play a big role in many industrial mixing processes. In such systems, knowledge of the gas volume fraction, its distribution and its eventual effect on mass transfer and reactions, is absolutely essential. Experimental measurements have given detailed information on many systems, resulting in numerous correlations which are commonly used in the design process. However, these correlations are very much limited to the size, type and character of the laboratory or pilot scale system from which they were created. This leaves process engineers with the task of ascertaining if an alternative design will meet all the required process conditions or not. Computational fluid dynamics (CFD) simulations give process engineers the ability to investigate virtual designs at a plant scale, using computer models, including modeling coalescence and breakup.
Turbulence modeling and its implications within the marine industry
Turbulence modeling is an essential element of any computational fluid dynamics (CFD) simulation of practical industrial problems. However, the selection of the most appropriate model is not a trivial task. In this On-Demand webinar, we will be looking at a number of fundamental aspects of turbulence modeling and how they affect the solution. We will make the distinction between statistical (essentially RANS models) and scale-resolving simulations (LES, DES). We will be presenting the most important aspects of the wall-treatment - with and without roughness - and will address the main...
The widespread adoption of modeling and simulation in life sciences on clinical and trial studies is at an embryonic stage, but that could soon be changing. Cardiovascular device design historically involves many iterations from experimental lab work on the benchtop to animal trials before a device gets approved for human/clinical trials. Finite element analysis (FEA) simulation has become more prevalent in recent years, followed by computational fluid dynamics (CFD) and fluid-structure interaction (FSI) modeling.

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