Electronics Cooling

Fluid and Thermal Modeling for Electronic Design

SINDA/FLUINT has been widely used for thermal modeling of electronics in the aerospace industry for decades. FloCAD® differentiates our product from other network style solvers by expanding the applicability of the code to ground-based electronics with convective environments, liquid cooling, and two-phase cooling loops (including refrigeration, thermosiphons, and immersion cooling). The geometric interface of Thermal Desktop® provides 3D CAD methods for simulating air cooling and thermal behavior of electronic enclosures, PC boards, heat sinks, and electronic racks.

Our suite of tools provides the unique ability to perform integrated thermohydraulic modeling of enclosures, capturing both the thermal and fluid aspects of mass and heat transfer. The user-friendly interface provides the designer the ability to quickly model a system yet provides the flexibility to easily perform sensitivity parametrics, optimization, and other high level operations related to sizing and reliability estimation.

Immersion-cooled Electronics

You have the ability to model fans, pumps, ducts, valves, filters, and other miscellaneous loss elements. Fluids may be selected from the built in property data base or the user may specify his/her own fluid properties. The most common choices for air cooled electronics include dry and moist air (including condensation and other psychometric effects), and for coolant loop fluids choices include water, water-glycol, PAO, 3M's NOVEC® fluids, etc. Even two-phase systems such as vapor compression cycle refrigeration systems can be modeled quickly and reliably.

Highlights of capabilities

  • An inexpensive fast-to-model and fast-to-solve alternative to CFD for air-cooled electronics
  • Fully parametric for easy model changes
  • The only piping network code for coolant loops and heat pipes that lets you lay out 1D lines within 3D thermal/structural geometry
  • Best-of-class design and analysis software for vapor compression refrigeration cycles and other two-phase systems such as spray cooling loops, immersion cooling systems, heat pipes, loop heat pipes, and thermosyphons
  • Best-of-class CAD-based and FEM-compatible thermal radiation, conduction, and contact resistance modeling tools
  • Advanced analysis methods for sizing/optimization, automated model calibration to test data, and statistical design including tolerancing and reliability studies

Sample Model

For more information:

dispersed vs. coalesced front

Tuesday, June 26, 2018, 1-2pm PT, 4-5pm ET

This webinar describes flat-front modeling, including where it is useful and how it works. A flat-front assumption is a specialized two-phase flow method that is particularly useful in the priming (filling or re-filling with liquid) of gas-filled or evacuated lines. It also finds use in simulating the gas purging of liquid-filled lines, and in modeling vertical large-diameter piping.

Prerequisites: It is helpful to have a background in two-phase flow, and to have some previous experience with FloCAD Pipes.

Register here for this webinar

FloCAD model of a loop heat pipe

Since a significant portion of LHPs consists of simple tubing, they are more flexible and easier to integrate into thermal structures than their traditional linear cousins: constant conductance and variable conductance heat pipes (CCHPs, VCHPs). LHPs are also less constrained by orientation and able to transport more power. LHPs have been used successfully in many applications, and have become a proven tool for spacecraft thermal control systems.

However, LHPs are not simple, neither in the details of their evaporator and compensation chamber (CC) structures nor in their surprising range of behaviors. Furthermore, there are uncertainties in their performance that must be treated with safety factors and bracketing methods for design verification.

Fortunately, some of the authors of CRTech fluid analysis tools also happened to have been involved in the early days of LHP technology development, so it is no accident that Thermal Desktop ("TD") and FloCAD have the unique capabilities necessary to model LHPs. Some features are useful at a system level analysis (including preliminary design), and others are necessary to achieve a detailed level of simulation (transients, off-design, condenser gradients).

CRTech is offering a four-part webinar series on LHPs and approaches to modeling them. Each webinar is designed to be attended in the order they were presented. While the first webinar presumes little knowledge of LHPs or their analysis, for the last three webinars you are presumed to have a basic knowledge TD/FloCAD two-phase modeling.

Part 1 provides an overview of LHP operation and unique characteristics
Part 2 introduces system-level modeling of LHPs using TD/FloCAD.
Part 3 covers an important aspect of getting the right answers: back-conduction and core state variability.
Part 4 covers detailed modeling of LHPs in TD/FloCAD such that transient operations such as start-up, gravity assist, and thermostatic control can be simulated.