FloTHERM optimizes thermal design of electronic devices

1. Overview

FloTHERM is a powerful 3D simulation software for thermal design of electronic components and systems. Engineers can quickly and easily create virtual models, run thermal analysis, and test design changes early in the design process before any physical prototype is built. FloTHERM uses advanced CFD (computational fluid dynamics) technology to predict airflow, temperature, and heat transfer of components, PCB boards, and complete systems, as shown in Figure 1.

Unlike other thermal simulation tools, FloTHERM is an analysis tool designed specifically for a variety of electronic applications, including:

◎Computers and data processing;

◎Telecommunication equipment and network systems;

◎Semiconductor equipment, integrated circuits (ICs) and components;

◎Aerospace and defense systems;

◎Automobile and transportation systems;

◎Consumer electronics.

FloTHERM is distinguished by its expertise, intelligence, and automation, which distinguish it from other traditional analysis software. These features can help thermal design experts maximize their productivity, help mechanical design engineers minimize the learning process, and provide customers with the highest return on investment in the analysis software industry.

In small and medium-sized enterprises, the return on investment in FloTHERM is several times the investment cost in one year. The larger the company, the faster the cost recovery. Users can experience the amazing benefits of using FloTHERM to solve electronic thermal design problems in the following aspects:

◎ Solve thermal design issues before producing hardware;

◎Reduce redesign work and reduce the cost per unit of product;

◎ Enhance reliability and improve overall engineering design;

◎Significantly shorten time to market. Modeling Function #e#2. Modeling Function

1.SmartParts

FloTHERM software provides parametric model creation macros (SmartParts) specifically for thermal analysis of electronic devices, which can quickly and accurately model a large number of electronic devices. SmartParts technology is applied to: heat sinks, fans, printed circuit boards, thermoelectric coolers, chassis, components, heat pipes, perforated plates and chips.

SmartParts devices are the result of more than 20 years of experience in electronics cooling modeling by the Mechanical Analysis Division of Mentor Graphics, and are designed to improve modeling efficiency, minimize solution time, and maximize the accuracy of results.

Key features include:

◎SmartParts complete cluster (parametric model creation macro);

◎Multi-level SmartParts devices (simple and detailed models can be provided for the same project);

◎Explorer-style project manager with drag-and-drop functionality;

◎CAD style, mouse drawing board and drag-and-drop function to create and operate models;

◎Multiple embedded localized grids greatly improve the computing efficiency and the ability to handle complex structures while ensuring the computing accuracy;

◎Model library contains thousands of FloTHERM models of devices and basic shapes, such as fans, blowers, components, heat sinks, materials and thermal interface materials;

◎ The mesh mode associated with the object enables modeling and mesh generation to be completed in one step.

2. Intelligent MCAD and EDA interface

FloTHERM has the best MCAD and EDA (Electronics Design Automation) interfaces in the industry. FloTHERM is not only compatible with Pro/ENGINEER, Solidworks, CATIA and other mainstream MCAD software data, but also supports model import and export. In addition, FloTHERM's EDA interface not only supports the import of IDF format PCB board models from EDA software, but also can directly read detailed models such as routing, device parameters and vias from software such as Allegro, Board Station and CR5000 through the interface.

3. Grid

FloTHERM uses orthogonal grid technology, the most stable and efficient numerical solution grid technology today, and also uses advanced non-continuous embedded grid and Cut Cell grid cutting technology. The localized grid function can further refine the grid when necessary to minimize the solution time.

FloTHERM software is equipped with semi-automatic mesh technology specifically for the electronics cooling industry. FloTHERM mesh is closely associated with SmartParts, and mesh generation is handled as a step in modeling in FloTHERM, and the user can control the degree of mesh refinement. This technology is intuitive and simple, meeting the needs of engineers to focus on design.

Operating traditional CFD software requires a lot of time and expertise, on the contrary, FloTHERM mesh generation is fast and the mesh quality is stable. At the same time, FloTHERM is the only analysis software that uses object-associated mesh mode, avoiding the need to regenerate the mesh when the model is modified.

3. Solver and Optimization Design

1. Parametric analysis and optimization

SmartPart-based modeling and structured Cartesian grids allow the FoTHERM model to use DOE (Design of Experiments, DOE) technology. Experimental design is a structured method to determine the relationship between design parameters (such as the number of heat sink fins and vent locations) and results (such as component temperature and fan flow). After using DOE technology, FloTHERM changes the design variables based on the original model and solves a large number of models with different parameters, effectively assisting users to explore a wide range of design spaces. This provides important information for comparing the analysis results of models with different design parameters, thereby minimizing the number of simulation models that need to be solved. At the same time, this also lays the foundation for the use of powerful response surface optimization design methods and sequential optimization methods. DoE optimization design automatically calculates the best solution based on the user's design.

FloTHERM extends this optimization capability by computing a response surface of all relevant results. Response Surface Optimization (RSO) is a numerical equation extracted from the DOE results to evaluate thermal design solutions anywhere in the design space in real time. Users can combine real-time 2D and 3D contour plots with the response surface structure to set the values ​​of design parameters using a sliding scale. The response surface also fully supports the mathematical optimization of user-defined cost functions, allowing the optimal solution to be evaluated without solving additional cases.

It can also perform automatic sequential optimization (SO) of the cost function. This gradient-based method will build a new model for different variables of the original model and run it to solve. This method can accurately select and determine the optimal thermal design solution. Sequential optimization can help understand the design constraints (such as maximum component temperature) and include this information in the optimal solution automatically selected by the software. See Figure 2.

2. Solver

For more than 20 years, FloTHERM's solver has been dedicated to solving electronic equipment cooling applications. The solver is based on a Cartesian grid system, with accurate calculation results and the fastest calculation speed per unit grid in the world. For large-area irregular models, FloTHERM uses "localized" grid technology. This technology can generate matching, nested and non-continuous grid interfaces between components in different solution domains. In view of the thermal coupling characteristics within the electronic system, FloTHERM currently uses a prior coupling residual algorithm and flexible multi-grid loop technology to deal with this problem. Practical, unique and accurate solution terminal standards can quickly generate results to meet actual engineering needs.

3. Transient analysis

FloTHERM’s powerful transient analysis capabilities enable it to predict a wide range of transient behaviors. The information corresponding to the change in heat dissipation over time can be imported into the software in a “.csv” format file to define the heat dissipation over time. Based on this, accurate reports on component temperature changes over time can be generated, rather than the energy consumption based on a constant state as provided in the past.

Key features include:

◎Simultaneously solve the main forms of heat transfer, including convection, conduction and radiation;

◎The solution terminal can be selected as the convergence based on the user-defined detection point;

◎The ability to analyze cooling systems containing multiple cooling media;

◎The ability to simulate turbulent or laminar flow;

◎All variables in linear gradient, energy increase, exponential increase, sinusoidal curve, periodic change, or imported ".csv" files that change over time can be defined as transient variables;

◎Fully automatic radiation heat exchange and calculation of radiation heat transfer coefficient;

◎Automatically load boundary conditions for solar radiation projects. Visualization #e#4. Visualization

FloTHERM visualization post-processing module is developed to speed up the thermal design of electronic equipment. Fully realistic models, 3D flow animations, tools for handling dynamic temperature changes, and flow results help engineers quickly and efficiently find thermal design problems and present design modifications in a visual form. Dynamic streamlines and tracer particle motion diagrams facilitate communication between engineers and colleagues who have a solid foundation in thermal design.

Key features include:

◎Complex, three-dimensional air flow animation;

◎Animated outline diagram of heat transfer flow;

◎Isosurface maps and surface cloud maps;

◎Vectors or streamlines reflect airflow, and colors are used to distinguish temperature and speed;

◎Export animation in AVI format;

◎Dynamic tracer diagram helps users better understand the flow of complex airflow;

◎Image texture enhances realism.

FloTHERM visualizes the post-processed results (Figure 3), showing the airflow paths and using different colors to represent the flow velocity, providing engineers with information on how to layout the ventilation holes in the LED TV.

The cross-sectional view (Figure 4) shows the temperature distribution between the product components, the housing and the air due to conduction, convection and radiation.