Learn more about using Aavid Genie, a thermal design tool for designing and simulating heat sinks. Here are some of the answers to frequently asked questions on how to use Aavid Genie.
GENERAL GENIE QUESTIONS
What is the Aavid Genie?
The Aavid Genie is your thermal engineer in a bottle, which utilizes a cloud based system solver to simulate thermal solutions, i.e. heat sinks. Simply input your requirements and parameters, and the Genie will design your manufacturable heat sink and provide a full thermal report. Simulations are on a pay per solve basis and do not require any licensing fees. There are no minimum or maximum uses, you can use the Aavid Genie one time or over one thousand times in a year and just pay as you go.
Why should I use Aavid Genie?
Full blown thermal simulation software is expensive, has a steep learning curve, and takes a considerable amount of time to solve the simulation. Aavid Genie has a simple web-based interface that helps you build your heat sink, define your conditions, and conducts a thermal simulation within minutes. Unlike other thermal software, the Genie is on a pay per solve basis, so you don’t pay for a year-long license fee for an application you may rarely use.
What do I need to know before I use Aavid Genie?
The Genie saves your progress as you go so you can pick up and put down a project any time, even if you need to check an input. For a list of the inputs requested by the Genie, click here.
Thermal reports are free with your simulation. Drawings and models will also be made available for an additional fee. You can also request a quote, either for prototypes or production, directly from the application.
Additional credits can be purchased in the application through PayPal.
How do I start using Aavid Genie?
You can register and start right away with three free credits!
Does Aavid Genie have any software requirements?
Aavid Genie works best on the latest versions of Google Chrome, Mozilla Firefox, macOS Safari and Microsoft Edge. Aavid Genie is also compatible with Internet Explorer 11.
GENIE STEPS: PROJECT CONDITIONS
I have a range of environmental conditions, what should I tell Aavid Genie?
For conservative results, use the harshest potential conditions that are likely to affect your heat sink. Typically this means the highest elevation and highest temperature that the devices or end product will experience. Read this blog post for more information on what environmental conditions to use in the Genie.
What does the Genie mean by “Working Envelope”?
This is the volume you have available for your heat sink. If you don’t have a fixed volume that you are working with, try using the largest preferred volume for your heat sink. Be sure to take into consideration any existing enclosures or ducts as those may dictate specific dimensions available to you. Read the blog post for more depth on what Aavid Genie means by working envelope.
How does Aavid Genie define depth?
In Aavid Genie, “depth” is the flow length of the fins. In other words, the depth is the direction perpendicular to the heat sink profile.
What does the Genie mean by “Total Load of Devices”?
Your device may be powered by 100W but is only dissipating 20W as heat. The 20W is what the heat sink will need to dissipate, so that is what your input to Aavid Genie should be. The total load of devices is further explained in this Aavid Genie Blog Post.
I have multiple devices, what should I input as the Total Heat Source Size?
In the project conditions page, Aavid Genie allows you to customize the size of your device. This is only to get an estimation of the power density and its effect on heat spreading in the base. You should select dimensions that will generate a footprint area equivalent to the sum of the footprint area all the devices will have on your base. This blog post goes into more detail about what inputs to use for your heat sources in Aavid Genie.
Why does Aavid Genie only apply Radiation to Natural Convection cases?
Aavid Genie will only apply the effects of radiation to heat sinks that have no forced flow, or are removing heat by natural convection. This is because the effect of radiation is a noticeable portion of heat transfer during natural convection, but fairly insignificant in forced convection situations.
I’m not sure if I should use the Maximum Case Temperature or Thermal Resistance?
It depends upon what value you have available to you, but they both will produce a maximum case temperature. If you have neither of these values, the Maximum Case Temperature may be the easier to calculate from the datasheet of your device. Read about how to calculate your maximum case temperature in the blog.
I only have the Maximum Junction Temperature of my device, how do I calculate the Maximum Case Temperature?
Learn more about how to read the thermal portion of your device’s datasheet in the blog.
How do I know what my Maximum Pressure Drop is?
Consider what is producing your airflow. If you aren’t using a fan, you have minimal pressure drop available to you. If you are using a fan or blower, you will need to consider a fan curve (PQ Curve). If you have an air flow for a whole system, you will need to consider the other elements in your system in relation to the fan curve.
GENIE STEPS: TECHNOLOGY SELECTION
How does Aavid Genie generate heat sinks for the Technology Selection Matrix?
Aavid Genie first tries to find a heat sink that meets your project conditions. If Genie cannot find a solution for that Technology/Flow combination, the box in the matrix will be colored red, with the condition that isn’t being met written in red text. Aavid Genie then reduces the amount of material of each Technology/Flow Combination, while still meeting the project conditions.
How do I pick a heat sink type/technology?
This is dependent on your requirements and preference. Within the application, you can have Genie “rank” the technology/flow combinations based on your key requirements such as “weight” or “size”. This allows you to choose the technology that best suits your needs.
How do I pick between natural or forced convection?
This is dependent on our application requirements and conditions. Applications that experience debris, require high reliability beyond what a fan would allow, or are extremely noise sensitive would be good candidates for natural convection. Additionally, smaller and lower power applications may not require forced convection. Read more about the comparison between natural convection versus forced convection.
What are extrusion heat sinks?
See this blog post for a full explanation of extruded heat sinks.
What are bonded fin heat sinks?
Read about bonded fin heat sinks in this blog post.
What are brazed fin heat sinks?
Read about brazed fin heat sinks in this blog post.
What are folded fin heat sinks?
See information regarding folded fin heat sinks in this blog post.
What are skived fin heat sinks?
Read about skived fin heat sink in this blog post.
What are zipper fin heat sinks?
See information about zipper fin heat sinks in this blog post.
GENIE STEPS: HEAT SINK DESIGN
Where are heat pipes placed in the base?
If you have a single heat pipe and single device, Aavid Genie will center the heat pipe on the device. To see how the Aavid Genie handles multiple heat pipes, see the Heat Pipe Placement Blog Post.
Should I have my heat pipe perpendicular or parallel to the fins?
This depends upon the application, but generally the heat pipes should be perpendicular to the fins so the heat pipe can spread the heat more effectively throughout the fins.
What does “Fixed Heat Sink Height” mean?
This option allows you to alter the base thickness or fin height without changing the total set height of the heat sink. This is important when working within a fixed height enclosure or duct. For example: in many server applications, boards must fit within predefined heights, so if a board and it’s solution need to stay within a 1U envelope, the heat sink height cannot be increased past that height.
GENIE STEPS: FLOW DEFINITION
Do I need a flow bypass for my heat sink?
If you have a fixed duct and your heat sink is smaller than this duct size, then you will have a bypass. Bypasses decrease the amount of airflow through the fins and decreases both the thermal performance (i.e. higher thermal resistance) and the pressure drop.
GENIE STEPS: HEAT SOURCES
What is a “Uniform Heat Load” and why would I add one to my heat sink?
A Uniform Heat Load in Aavid Genie allows you to account for additional smaller heat sources not worth individually modeling and defining in Genie, but collectively they contribute to the overall heat load. This will distribute the additional heat load uniformly across the heat sink base and offer a more accurate simulation of your heat sink’s thermal performance.
Do I need to include an interface resistance?
If you’re looking for quick answers and a general sense how your heat sink will work, you can omit a thermal interface resistance. Otherwise you should definitely include an interface resistance in your Aavid Genie Simulation. Unless there is something that prevents you from using any thermal interface material (TIM) in your application, you should always include TIM between your heat source and your heat sink.
Read more about TIMs, what they are, and how to use thermal interface materials in Aavid Genie in the blog.
Where am I placing my heat sources when I move them around on Aavid Genie?
The grey box represents the board or mountable area that the heat sink will cover. See how your heat sources are placed in our Aavid Genie blog post for a more visual answer .