OpenVPX Chassis Thermal Management: Dangerous Myths and Analytical Tools

High-performance OpenVPX systems generate significantly more heat than legacy VME platforms, making thermal management a critical part of system architecture—not an issue to solve later.

This white paper examines OpenVPX chassis thermal management for rugged defense and aerospace systems, including common cooling misconceptions, early-stage thermal criteria, cooling-method selection, heat-transfer principles, and analytical tools used to evaluate demanding applications.

What you’ll learn

• Why OpenVPX is different from VME: Understand why higher-power OpenVPX processing modules require greater attention to cooling and thermal design.
• Four common thermal-management myths: Learn why cooling cannot simply be addressed late in a program, why legacy chassis may be inadequate, and why natural convection is not suitable for every environment.
• How to define thermal requirements early: Evaluate power dissipation, payload cooling requirements, ambient temperature, altitude, airflow, pressure drop, coolant flow, and thermal interfaces.
• How cooling methods compare: Review natural convection, baseplate conduction, forced-air conduction, liquid cooling, Air Flow Through (AFT), Liquid Flow Through (LFT), and heat-exchanger approaches.
• How altitude affects cooling: See why decreasing air density at altitude reduces cooling-air mass flow and can dramatically change system thermal performance.
• How analytical tools reduce risk: Use thermal resistance, heat-transfer calculations, airflow analysis, and cooling-performance comparisons to support better chassis design decisions.

The white paper identifies four common myths surrounding OpenVPX thermal management and provides criteria for determining power dissipation, payload cooling, airflow, cold-plate conditions, and coolant requirements. It also compares multiple chassis cooling methods ranging from natural convection and forced air to conduction and liquid cooling.

Atrenne supports rugged OpenVPX chassis and enclosure development across a broad range of cooling technologies. Selecting the right thermal architecture early helps protect payload electronics, reduce qualification risk, and avoid costly redesign later in the program.