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About CFD Online

CFD Online is an online center for Computational Fluid Dynamics. Services include several discussion forums, a jobs database, a free CFD reference in the form of a CFD-Wiki, a news and announcement forum, an events calendar, and a comprehensive annotated link section with pointers to CFD resources around the world. CFD Online's goal is to offer high-quality web services to the CFD community. The site is independent and it is financed mainly by banner-ads.

Today CFD Online is the largest and most popular CFD site on the Internet. During a typical week the web site is visited by more than 81,000 people (unique IP addresses), downloading 336,000 web pages per week. In total there are more than 2,500 web sites around the world with links to CFD Online. In 2021 CFD Online celebrated 27 years of uninterrupted service to the CFD community! CFD Online continues to strengthen its position as the world's leading CFD portal. CFD Online is top-listed by all major search engines and has received many awards over the years.


In 2021 CFD Online has maintained the very strong traffic seen over the last 10 years. A small decline in traffic can be seen in the last couple of years, but CFD Online still delivers around 1.5 million web-pages per month to our visitors. The main reason for the decline is that academic research related to CFD has reduced a bit in the last years, and this has affected our traffic from universities negatively. Traffic from companies has not reduced in the same way. The bar chart above shows the 12-month trailing average of the number of web pages delivered from CFD Online per month over the last 23 years.

Note that these statistics exclude access from robots and common search engines like Google, Bing and Yahoo. This is necessary in order to give a true representation of the traffic from real humans. Otherwise the quickly growing traffic from Google and other search engine robots would completely overshadow human visitors.

Visitor Demographics

Visitors to CFD Online come from typical CFD sites from all over the world. The pie chart below shows the traffic distribution across different top-level domains. Further details about where traffic is coming from can be found in the web server statistics report at

The location of CFD Onlineā€™s visitors is similar to last year. A long-term trend is that more and more countries and companies are hiding behind anonymous numerical or network addresses. For example, most explicit traffic from China is now gone. We still have many users from China though, but they are hidden behind anonymous proxies. Traffic from US Academia has fallen over the precious years and now only accounts for 1%. In Europe Germany continues to grow and account for a large amount of the European traffic. On the browser side Chrome has completely taken over as the most popular browser with 70% of all traffic. On the OS side Windows is still the most common OS and Windows 10 adaption has increased from 58% to 65%. Linux traffic has reduced a bit from 13% down to 12%. Usage of mobile devices continues to be strong and Android + iOS now accounts for 13% of our traffic.


The pie chart below shows the relative number of page-downloads for the different services at CFD Online. In total, the discussion forums are still the most popular section, with 69% of all the page-views. The CFD-Wiki has 11%, the CFD Jobs Database 9%, the Events calendar 3%, the Links section 2%, and the News & Announcement section 1% of all page-views.

The traffic distribution between different services have not seen any large shifts in 2021 and are very similar to last year. CFD Online remains the most popular meeting place on the net for free and independent discussions about CFD. Users seem to prefer the open forums at CFD Online over closed forums run by code vendors. The following services are currently available at CFD Online:

News and Announcement Service

The largest free online CFD news service, with more than 5,000 news and announcements published since 2001. The news section currently has 5,200 unique visitors every month and more than 5,500 people are subscribed to the weekly email news-digest.

Discussion Forums

The most popular meeting place on the net for people interested in CFD. The forums have more than 778,000 archived messages in 202,000 threads from the previous 23 years.


CFD-Wiki is intended to eventually become the ultimate free CFD reference and text-book. The content is written collaboratively by thousands of users. CFD-Wiki contains more than 550 articles on various CFD related subjects. Many engineers and students use it as a valuable reference.

Links Section

The links section is very well known in the CFD world and continues to attract many return visitors year after year. It has been the largest collection of CFD links available on the net since it was introduced in 1994. In 2012 a major overhaul of the whole links section was done.

CFD Jobs Database

The CFD Jobs Database is the section that attracts most people. The CFD Jobs Database is visited by more than 1,400 job-seekers every day! It is a very good way to recruit CFD experts. The CFD Jobs Database has had about 180 open positions advertised throughout 2021.

Events Calendar

This service is intended to help students and professionals to find CFD related conferences, courses and workshops. Since the service was opened in 2002 more than 3,300 events have been advertised in it.

Tools Section

The tools section contains online tools useful for CFD engineers and students: Two calculators, a unit converter, a Y+ estimation tool and a tool to convert and estimate turbulent properties

Feeds Section

The feeds section was launched in 2012; it contains aggregated feeds of CFD news-sources, blogs, vendors, jobs and journals. This service has become an important tool to help people stay up to date.


CFD Online is only responsible for the documents on this server, not for any of the external references. All opinions expressed are personal opinions.

Software and Hardware

Our servers, installed in June 2015, are working very well. The site is hosted on a virtual server based on Centos KVM technology. The virtual server runs on a dedicated production server with a failover system to quickly switch over to a backup server that stands online ready to take over in case of hardware problems. The production server has two mirrored RAID1 SSD disks and plenty of memory.

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Our production server has a Xeon E3-1270v3 CPU, 32GB ECC RAM, and two mirrored RAID1 enterprice SSD disks to ensure a quick and reliable delivery of pages. We have plenty of room to grow and increase our traffic in the future.


Please tell us what you think about this site. Contact information can be found on the contacts page. We appreciate any comments or suggestions. It is always nice to get some feedback and not only strange connections from someone.far.away.sirius_b
"I consider it the obligation of scientists and intellectuals to ensure that their ideas are made accessible and thus useful to society instead of being mere playthings for specialists."

- Bjarne Stroustrup, from "Design and Evolution of C++"