This article brings you some information on how PDM Analysis bridges the technological gap between numerical analysis-based design and the industrial compressor engineering requirements for robust and flexible analysis tools. A recent Aeronautical Engineering graduate at City, University of London used PDM Analysis software SCORG and cloud platform SCORG alto for his Final Year Project. An insight into his experience and learning curve during the past year has been presented.
Over the past few years, PDM Analysis has created and delivered two outstanding products SCORG and SCORG alto. They can help you design and analyse various positive displacement machines, including compressors, expanders, pumps, motors and more.
SCORG is a specialised software designed to minimise efforts and maximise the efficiency of the design process. It enables:
- grid generation
- geometry analysis
- preliminary thermodynamic evaluation
Based on SCORG software, the SCORG alto platform was launched in 2020. This online platform is hosted on Microsoft Azure, giving the user their own virtual computer with the latest edition of SCORG software and learning resources pre-installed. Users can execute their ideas into solutions online from anywhere in the world. That is a real game-changer in the industry during the current COVID-19 pandemic situation and beyond.
Figure 1: Advantages of SCORG alto
Mr Ahmed Rohaib, a BEng Aeronautical Engineering final year student at City, University of London, formulated his Final Year Project about Cloud Computing – CFD analysis of a Twin-Screw Compressor. His thesis aimed to give an individual or a company information about whether to use an online platform or a traditional local computing setup to design and analyse positive displacement machines using SCORG software.
During his project that spanned over a year, more importantly during the peak of the COVID-19 pandemic, Rohaib informed us that he had experienced the following advantages of SCORG:
Users can conduct their simulations comfortably from any device and any part of the world. One condition which must always be met to access the virtual computer is the internet connection.
SCORG alto portal has an appealing colour scheme and an easy-to-follow layout to find all helpful information easily. When placing the order for a virtual machine, the user can decide which location they want their virtual machine to be at. SCORG alto has virtual machines all over the world, covering all continents. Selecting the closest location provides the user with the best quality connection to have a smooth experience using the virtual machine. Moreover, SCORG alto makes sure that the user will always have the latest version of SCORG installed on their virtual computer without intervening.
Figure 2: Dashboard of the SCORG alto
On-demand licensing system
The user can get the first license with as few as the two-week lease. Subsequent leases are available on a weekly basis. This tool is economical and easily accessible to freelancers, consultants, students and many others. Moreover, multiple users can use a single virtual machine to access SCORG simultaneously in an educational or corporate environment.
Azure Cloud Services and Data Protection
Your data is safe with built-in security services in Azure and SCORG alto platforms. Azure arranges data in the best possible manner and protects it in the virtual storage machine. Cloud storage saves data for a prolonged period. Also, it secures the information against malware and viruses roaming on the internet.
Data recovery and backups
Every company needs a reliable and solid system to prevent data leakage or loss. SCORG alto offers automatic backup of data and site recovery with it. If in any circumstance, the data is lost, there are ways to get it back. Azure will assist in getting back your data from a secondary domain if it vanishes from the primary one. It works better than solutions used on local platforms where backing up data is usually a manual process, and the backup is saved on the PC itself. This takes up double the storage space as the original file size, and if a virus infects the PC, all the data can be lost.
Figure 3: Microsoft Azure Backup – Three pillars of security
When performing CFD simulations, the file sizes are rather large and start filling the hard drive with every iteration. On a local PC, before you know it, there is insufficient space to save these files. With SCORG alto storage is never a problem. If there is not enough space, you can always upgrade your storage. Furthermore, there is no maximum storage capacity. Effectively the user has the freedom to buy unlimited storage.
On average, the user can expect from Microsoft Azure a minimum download speed of 400 Mbps. A minimum upload speed of 800 Mbps means the user will spend minimal time downloading files from the internet.
The ping measures the latency delay between the user making a request and the device getting a response. Thus, the lower the ping, the more responsive the system is. A 2-millisecond ping is almost perfect, and the user will not notice any delay in system response time.
Speed of calculations
When producing CFD simulations, efficiency is key. These simulations can take days to obtain the required results. Multiple tests were carried out between the two platforms to see which could go through the set number of iterations in the shortest amount of time.
Comparison of the simulation results of the dry and oil compressor shows that the virtual computer is faster. On average, the virtual computer took 10 minutes less for the dry and 26 minutes less for the oil-injected compressor to produce the same results as the local computer.
Also, both platforms had different thermodynamic calculation times. The difference of 3.9 seconds is significant during parametric simulation when multiple cases are calculated.
Figure 4: Time to produce thermodynamic results
During the simulations, the virtual computer used between 50-60% of the CPU memory compared to the local PC, which used just 28% of the total CPU memory in the case of the 2 cores dry compressor.
Figure 5: Hardware utilisation for a dry compressor using 2 scores (SCORG alto)
Figure 6: Hardware utilisation for a dry compressor using 2 scores (Local PC)
When it comes to the technical comparison of two systems, simulations on the virtual machine are usually run faster. All their processing power is dedicated to calculations compared to local machines where other applications and background processes must be maintained by the system. There is a visible increase in RAM usage for oil-injected cases compared to dry compressor calculations. This might be due to more complex equations used when additional fluid is involved. It is worth mentioning that hardware available when using a virtual machine is regularly updated. It constantly improves execution times and user experience. At the same time, local devices usually use unmodified resources available at the time of purchase.
Watch the interview with Ahmed Rohaib about the result of his project and experience with using cloud software. Also, you can read the transcript from this video.
In case you are a STEM student and looking forward to working on twin screw machines such as compressors and expanders, register yourself on the SCORG alto portal and avail of the 50% discount for an academic license.