Category Archives: Consulting

CFD With Analytical Modeling Gives ATS Edge

In January, Advanced Thermal Solutions, Inc. (ATS) and engineering simulation software leader Future Facilities announced that ATS had purchased multiple seats of 6SigmaET, an electronics thermal simulation software, adding to its CFD (computational fluid dynamics) capabilities.


ATS engineers are now using 6SigmaET to perform CFD on electronics cooling applications to find optimized thermal solutions for customers. (Advanced Thermal Solutions, Inc.)

In a joint press release from the two companies, ATS founder and CEO Dr. Kaveh Azar said, “We have decades of experience with a broad base of commercially available CFD tools. For the electronics thermal management analyses, 6SigmaET showed excellent agreement with our empirical and analytical modelling.

He added, “We were equally impressed with its ease of use and a short learning curve. Our engineering team was able to apply the tool to different levels of simulation extending from component to system level modelling. The speed of convergence and ease of use of 6SigmaET, have made it the first CFD software to use.”

6SigmaET becomes the lead thermal simulation software for ATS engineers dealing with standard electronics cooling challenges. ATS engineers will be able to quickly and efficiently simulate junction and ambient temperatures across boards and components or define airflow to find fan operating points or get a better understanding of pressure drop in a system.

Dr. Azar continued, “We always want to be working with the best breed of tools to deliver the innovative, high-quality and cost-effective thermal management and packaging solutions our customers expect. As a result, this addition is good news for our customers. The rich features of the 6SigmaET thermal simulation package not only enable us to do more when it comes to simulation, but also allows us to further deliver the solution to our clients in a shorter time interval. It is my highest compliment to 6SigmaET development team for putting together such a robust and effective software.”

Adding 6SigmaET to ATS CFD capabilities, which also includes FloTHERM from Mentor and Autodesk CFD (formerly CFdesign), enables engineers to save customers time in the design phase and makes it easier for ATS engineers to devise optimal thermal solutions.

ATS engineer Anatoly Pikovsky said, “Visual is definitely a great thing to have. If you look at this temperature map, for instance, you can look at the defined map and say right away, okay I have a very high temperature right in the middle.”

Pikovsky, who was working on Autodesk CFD to design a customized cold plate for a customer, demonstrated how the software allows for him to analyze the pattern of fluid flow through complex geometries that were imported from SolidWorks drawings. He used the software to show hot spots and fluid velocity and how small changes, such as the number of fins within the cold plate, could alter the results.

Field Application Engineer Vineet Barot explained that he used 6SigmaET on a board in which there was pressure drop coming from vents at the end of the board. In simulations, he was able to add fins to the heat sink without altering the fan operating point and quickly provide a thermal solution that was presented to a customer. He said, “If you had a standard 1-U chassis you can build it from scratch and run it in half an hour.”

While CFD continues to evolve to handle more complex problems, while also becoming easier to use for engineers, simulations are only part of the solution.

ATS engineers also perform analytical modeling, literally putting pen to paper with basic thermodynamic equations, to define the problem and provide a reference point for simulations. Coupling analytical and computer modeling is what sets ATS apart from its competitors because it ensures that thermal solutions provided by CFD are correct.

“CFD will give you a solution, whether it’s right or wrong, it will give you a solution,” Pikovsky said. “That’s the way it’s designed. Analytical coupled with CFD gives you a good reference point to know whether you’re in the ballpark.”

Analytical modeling also speeds up the process of finding an optimized solution. Rather than spending days or weeks plugging in different fin numbers and heights or trying numerous heat sink geometries, ATS engineers can define a small range of iterations, limiting the variables for CFD, to avoid countless simulations, each of which could take hours to run.

Pikovsky said, “Maybe you’ve designed a heat sink for certain airflow and you want to determine the number of fins. You can do it with CFD, but you start varying fins and it’s going to take you days. Analytical is great because you can determine the optimal number of fins and start CFD with that.”

CFD is a critical component of ATS thermal consulting and design services. 6SigmaET has quickly been adopted by ATS engineers as the lead software and been used in the design of thermal solutions for a number of customers in the past few months.

But, it is the combination of CFD with ATS engineers’ emphasis on analytical modeling that has made ATS a leader in the thermal management of electronics.

For more information about Advanced Thermal Solutions, Inc. (ATS) thermal management consulting and design services, visit or contact ATS at 781.769.2800 or

Thermal Questions? ATS Has Your Answers

If you have any questions about Advanced Thermal Solutions, Inc. (ATS) liquid or air cooling products, next-generation thermal instruments, or expert thermal consulting and design services, contact ATS today by email at

Cold Chains: How Various Industries Keep Products Cold During Shipping

By Norman Quesnel
Senior Member of Marketing Staff
Advanced Thermal Solutions, Inc. (ATS)

A cold chain is a series of packaging, shipping, and distribution steps, all conducted at controlled temperatures. A successful cold chain keeps products within their required temperature ranges even when shipping between continents or hemispheres. Cold maintenance preserves the optimal shelf lives of produce, seafood, frozen food, pharmaceuticals, and other products that must be kept constantly chilled or frozen to maintain their quality.

Cold Chains

Fig. 1. Components in a KoolTemp Insulated Container from Cold Chain Technologies. [1]

About 70% of all food consumed in the United States is handled by cold chains. Without proper cooling or freezing, most of this food would show signs of perishing before reaching its end user and could potentially be inedible and unsafe.

For pharmaceuticals, consider a vaccine supply shipped to a third world country without a cold chain infrastructure. Excess exposure to heat could make the vaccine inactive and, even worse, this may not be discovered until after the shots have been distributed.

It is critical for shipping parties (food companies, drug companies, et al.) to have sufficient scientific knowledge of their products and the environments they will travel through before reaching the end users. With that knowledge in hand, the cold chain can accommodate almost every product that must ship under cold temperatures.

Fig. 2. There Are Four Temperature Range Standards Commonly Used to Designate Optimal Transport Temperatures in the Cold Chain. [2]

Cold transportation and storage standards have been developed by the U.S. as well as countries in Europe and Asia. Guidelines are also provided by the World Health Organization (WHO). The most common temperature standards in the food cold chain are “banana” (13°C), chill (2°C), frozen (-18°C) and deep frozen (-29°C); each is related to specific product groups. These standards are mainly used in the produce (agricultural) industry.

For vaccines and other pharmaceuticals, the cold chain must be compatible with labeled instructions such as “Store in a refrigerator, 2°C to 8°C (36°F to 46°F),” or “Store in a freezer, -25°C to -10°C (-13°F to 14°F).”

Food and pharma providers apply science to make products that will better withstand warmer temperatures. But most of these products must still be kept cold or frozen once they are packaged and shipped out. Poor temperature conditions or delays of an in-shipment food product or a drug can damage that product enough so it loses any market value or utility. [3]

Fig. 3. An Insulated Box Liner from IPC Helps Keep Produce Cool During Shipment. [4]

The pharmaceutical industry factors in potential temperature fluctuations during transit and storage. For many of pharma products, there is an MKT (mean kinetic temperature). This is a “thermally equivalent” temperature that degrades the same amount of a drug as degraded by the different temperatures during a particular period of time. [5]

MKT is a complex calculation with many data points. Per Wikipedia, the mean kinetic temperature can be expressed as shown in Figure 4:

Fig. 4. The Mean Kinetic Temperature (MKT) Expresses the Effect of Temperature Fluctuations During Storage and Transit of Perishable Goods. [6]

Here is a simple analogous example of working out an MKT:

A dozen eggs sat:

  • In a 20°C room for two hours.
  • In a 2°C refrigerator for four hours.
  • And on a 25°C loading dock for one hour.

Using MKT, a company can calculate that the temperature profile of the eggs was “thermally equivalent” to storing them at 10.096°C for seven hours. [7]

Cold Chain Packaging

Ensuring that a shipment will remain within a temperature range for an extended period of time comes down largely to the type of container and the refrigeration method. Duration of transit, the size of the shipment, and the outside temperatures experienced are all important in deciding the type of packaging. Examples of packaging used in shipping range from small insulated boxes that require dry ice or gel packs, rolling containers, or a 53-foot truck with its own refrigeration unit.

Fig. 5. Canadian Vaccine Storage and Handling Guidelines for Immunization Providers. [8]

The major cold chain technologies used for providing a temperature controlled environment during transport involve a range of materials and vehicles. Below is a quick summary [9]

Dry ice – Solid carbon dioxide is about -80°C and is capable of keeping a shipment frozen for an extended period of time. It is widely used for the shipping of pharmaceuticals, dangerous goods, and foodstuffs and in refrigerated unit load devices for air cargo. Dry ice does not melt, instead it sublimates when it comes in contact with air. [10]

Gel packs – Large shares of pharmaceutical and medicinal shipments are classified as chilled products. This means they must be stored in a temperature range of 2-8°C. The common method to provide this temperature is to use gel packs, or packages that contain phase-changing substances that covert from solid to liquid and vice versa to control an environment. Depending on the shipping requirements, these packs can either start off in a frozen or refrigerated state. Along the transit process they melt to liquids, while at the same time capturing escaping energy and maintaining an internal temperature. [11]

Eutectic plates – These are also known as cold plates. The principle is similar to gel packs, but the plates are filled with a liquid and can be reused many times. Eutectic plates have a wide range of applications, such as maintaining cold temperature for rolling refrigerated units. They can also be used in delivery vehicles to keep temperature constant for short periods of time. [12]

Liquid nitrogen – An especially cold substance at about -196°C, it is used to keep packages frozen over a long period of time. Liquid nitrogen is commonly used to transport biological cargo such as tissues and organs. It is considered a hazardous substance for the purpose of transportation. [13]

Quilts – These are Insulated pieces that are placed over or around freight to act as a buffer against temperature variations and to maintain a relatively constant temperature. Using quilts, frozen freight will remain frozen for a longer time period, often long enough to make the usage of more expensive refrigeration devices unjustifiable. Quilts can also be used to keep temperature sensitive freight at room temperature while outside conditions can substantially vary (e.g. during the summer or the winter). [14]

Reefers – Their name derived from ‘refrigeration’, reefers are temperature controlled, insulated vans, small trucks, semi-trailers or standard ISO containers. They are specially designed to allow temperature-controlled air circulation maintained by an attached and independent refrigeration plant. A reefer is therefore able to keep the cargo temperature cool and even warm. The term reefer increasingly applies to refrigerated 40-foot ISO containers with the dominant size being 40 high-cube footers (45R1 being the size and type code). A reefer carries around 20-25 tons of refrigerated cargo and is fully compatible with the global intermodal transport system, which implies a high level of accessibility to markets around the world. [15]

The first reefer ship for the banana trade was introduced in 1902 by the United Food Company. This enabled the banana to move from an exotic fruit that had a small market, because it arrived in markets too ripe, to one of the world’s most consumed fruit. Its impact on the reefer industry was monumental.


It takes time and coordination to efficiently move a shipment and every delay can have negative consequences, notably if this cargo is perishable. The greater the physical separation, the more likely freight can be damaged in one of the transport operations involved. Some goods can be damaged by shocks while others can be damaged by undue temperature variations.

For a range of goods labeled as perishables, particularly produce, quality also degrades with time. Ensuring that cargo does not become damaged or compromised in shipment, businesses in the pharmaceutical, medical and food industries are increasingly relying on the cold chain.

A recent industry forecast sees the global cold chain market growing by 7% every year, reaching $340 billion by 2025. [16]


For more information about Advanced Thermal Solutions, Inc. (ATS) thermal management consulting and design services, visit or contact ATS at 781.769.2800 or

In the ATS Labs – Where Thermal Solutions Advance to Meet Industry Demands

Thermal management innovations need to match the rapid pace at which the electronics industry is advancing. As consumers demand new and more powerful devices or greater amounts of information at faster speeds, cooling solutions of the past will not be enough. Today’s cooling solutions must be smaller, lighter, and offer higher performance, but also need to be cost-effective, meet demanding project specifications, and be reliable for many years.

Advanced Thermal Solutions, Inc. (ATS) understands the importance of creating cutting-edge thermal solutions for its customers and has geared its thermal design capability and its research and development to match the innovations taking place in electronics design.

ATS Labs

An ATS engineer assembles a rig for testing cold plates in one of ATS’ six state-of-the-art labs. (Advanced Thermal Solutions, Inc.)

To meet the need for innovative solutions, ATS engineers are hard at work in the company’s six state-of-the-art laboratories at the ATS headquarters, located in Norwood, Mass. (south of Boston). Thermal issues of all kinds are recognized, broken down, and resolved and cooling solutions are designed, simulated, prototyped, and rigorously tested in these research-grade facilities.

When someone thinks of a research lab, the initial picture is scientists in white coats working for major corporations, such as IBM, Microsoft, or Google, but the development of new ideas is an essential tool for any company in the technology field. Working with empirical tests in a lab environment pushes concepts from the white board or the computer screen to reality. There comes a time when engineers need to produce tangible data to ensure that a design works as planned.

ATS thermal engineers are no different. They use state-of-the-art instruments and software in each of the six labs to conduct a long list of characterization, quality-assurance, and validation tests. In addition to finding custom cooling solutions for customers, ATS engineers produce thermal management products for commercial uses, including a variety of next generation heat sink, heat pipe, vapor chamber, and liquid cooling designs.

Engineers test ATS instruments using a wind tunnel and sensors in the Characterization Lab. (Advanced Thermal Solutions, Inc.)

Among the most common tests performed in the ATS labs are:

• Measurements of air velocity, direction, pressure and temperature;
• Characterization of heat sink designs, fans and cold plates
• Flow visualization of liquid and air flow
• Image visualization characterization using infrared and liquid crystal thermography.

Many of the instruments that these tests are performed on were designed and fabricated by ATS. That includes open-loop, closed-loop, and bench-top wind tunnels; the award-winning iQ-200™, which measures air temperature, velocity, and pressure with one instrument; and the thermVIEW™ liquid crystal thermography system. Engineers also use specially-designed sensors, such as the ATS Candlestick Sensor, to get the most accurate analysis possible.

Smoke flow visualization tests run in ATS wind tunnels demonstrate how air flows through a system. (Advanced Thermal Solutions, Inc.)

Heat pipes and vapor chambers are increasingly common cooling solutions, particularly for mobile devices and other consumer electronics, and ATS engineers are working to expand the company’s offerings for these solutions and to develop next generation technology that optimizes the thermal performance of these products. This research involves advanced materials, new fabrication methods, performance testing, and innovative designs that are ready for mass production.

ATS engineer Vineet Barot sets up a thermal imaging camera for temperature mapping studies in the lab. (Advanced Thermal Solutions. Inc.)

ATS has also developed products to meet the growing demand across the electronics industry for liquid cooling systems. From new designs for recirculating and immersion chillers to multi-channel cold plates to tube-to-fin heat exchangers, ATS is continuing to expand its line of liquid cooling solutions to maximize the transfer of heat from liquid to air and researching new manufacturing methods, advanced materials, and other methods of enhancing the technology.

As liquid cooling technology has grown, ATS has met this demand with new instruments and lab capabilities, such as the iFLOW-200™, which measures a cold plate’s thermal and hydraulic characteristics, and full liquid loops to test ATS products under real-world conditions.

ATS Labs

ATS engineer Reza Azizian (right) works with intern Vladislav Blyakhman on a liquid cooling loop in the lab. (Advanced Thermal Solutions, Inc.)

The labs at ATS are up to even the toughest electronics cooling challenges that the company’s global customers present. Thanks to its extensive lab facilities, ATS has provided thousands of satisfied customers with the state-of-the-art thermal solutions that they demand.

For more information about Advanced Thermal Solutions, Inc. (ATS) thermal management consulting and design services, visit or contact ATS at 781.769.2800 or

Heat Sink Design: ATS Engineers Bring Ideas to Life

Marketing Communications Specialist Josh Perry sat down with Product Engineering Manager Greg Wong to discuss the process that Advanced Thermal Solutions, Inc. (ATS) engineers go through to create a heat sink and find a thermal solution for customers.

Watch the full conversation in the video below and scroll down to read the transcript of the interview.

JP: Greg, thanks again for joining us here in marketing to explain what it is that goes into designing a heat sink for a customer. So, how does that process begin?
GW: We usually start with a few basic parameters; we call them boundary conditions. So, we start with a few boundary conditions, basics like how much airflow we have, how much space constraint we have around a heat sink, and how much power we’re dissipating, as well as the ambient temperature of the air coming into the heat sink.

So, those are the real basic parts that we need to start out with and sometimes the customer has that information and they give it to us, and usually we double-check too, and then other times the customer has parts of the information, like they know what fan they want to use and they know what kind of chassis they’re putting it in and we take that information and we come up with some rough calculations so we can arrive at those things like air flow and stuff like that.

JP: When you get the data from the customer, how do you determine what the problem is, so that way you can move forward?
GW: We usually start out with an analytical analysis. So, we put pen to paper and we start out with basic principles of heat transfer and thermal resistance and stuff like that so we can understand if what we’re trying to achieve is even feasible and we can come up with some basic parameters just using that analytical analysis.

Like we can calculate what kind of heat sink thermal resistance we need or we can calculate how much air flow we need or, if we have several components in a row, we can calculate what the rough air temperature rise is going to be along that chain of parts. So, there’s a lot we can do when we get the basic information from the customer just on pen and paper.

JP: What’s the next step beyond analytical?
GW: Well, we can do some lab testing or a lot of times we also use CFD simulations and, if our customer has a model they can supply us, we can plug that into the CFD simulations and we can come up with an initial heat sink design and we can put that into the simulations as well and then we set those up and run them.

The great thing, having done these analytical analyses beforehand, we know what to expect from CFD simulations. So that way, if the simulations don’t run quite right, we already have an understanding of the problem, we know what to expect, because CFD is not 100 percent reliable.

I mean, you can go and plug all this stuff in there but you really have to understand the problem to know if the CFD is giving you a good result. So, oftentimes that’s the next stage of the process and from there we can actually produce low-volume prototypes right here in Norwood (Mass.), in our factory. We have CNC machines and manual milling machines, lathes, all that kind of stuff, and we can produce the prototypes and test them out here in our labs.

JP: How much of a benefit is it to be able to create a prototype and to be able to turn one around quickly like that?
GW: Oh, it’s great. I mean, if we had to wait to get parts from China it will take weeks to get. We can turn them around here in a few days and the great thing about that is we can test them in our labs and, you know, when it comes to getting results nothing beats the testing.

I mean, you can do analytical analysis, you can do CFD simulations, but when you actually test the part in a situation that is similar to what the actual thing is going to be that’s where the real meat comes down.

Heat Sink Design

ATS engineers take customer data and using analytical modeling and CFD simulations can design the right cooling solution to meet the customer’s specific thermal needs. (Advanced Thermal Solutions, Inc.)

JP: So, we test the prototypes before sending them out to the customer? We do the testing here or do we send it to them first?
GW: It all depends on what the customer requires. Sometimes the customer has a chassis that we really can’t simulate in our labs, so we might send the prototype heat sinks to the customer and the customer will actually put them into their system to test them out.

Other times, a customer might have a concept and they don’t actually have a product yet, so we’ll mock something up in our labs and we’ll test it and it all just depends what the customer needs and also how complex the problem is.

If it’s a simple heat sink and pretty simple airflow, we might not need to test that because we understand that pretty well, but the more complex the chassis is and how the airflow bends and stuff like that, the greater benefits we get out of lab testing.

JP: Well, I appreciate it Greg. Thank you for taking us through the process of making a heat sink and solving thermal problems for our customers.
GW: Sure Josh. We love seeing new thermal challenges and coming up with ways of keeping stuff cool.

For more information about Advanced Thermal Solutions, Inc. thermal management consulting and design services, visit or contact ATS at 781.769.2800 or