Aviation

Avionics/Aircraft Thermal Management

The thermal management of electronic systems is becoming one of the most limiting factors for military and commercial aircraft. This trend is driven by the integration of aircraft subsystems, the conversion of mechanical systems to their electrical counterparts, and the ever-present demand for systems with lower volume, mass, and power consumption requirements than previous designs. In addition, aircraft systems must withstand extreme operating conditions, such as wide temperature ranges and large-magnitude, variable-orientation acceleration in the form of shock, vibration, and sustained maneuvers.

Advanced Air Platforms from Left to Right: Lockheed Martin F-35 Joint Strike Fighter, Northrop Grumman RQ-4 Global Hawk, and Boeing AH-64 Apache

Advanced Air Platforms from Left to Right: Lockheed Martin F-35 Joint Strike Fighter, Northrop Grumman RQ-4 Global Hawk, and Boeing AH-64 Apache

Thermal Expertise:

Common thermal solutions can no longer keep pace with these increasing demands. There is a need for innovative, reliable and cost-effective thermal management solutions. ACT is meeting this challenge by providing solutions based on our extensive experience in the design and development of advanced thermal systems. We work closely with our customers to identify thermal issues and produce thermal management components that integrate seamlessly with their products. We rely on our breadth of thermal expertise to identify the best thermal solution to meet the requirements specified by our customers. Some areas of our expertise include heat pipes and related technologies, pumped single and two-phase systems, vapor compression systems, and thermal storage devices. Finally, all of our aviation and aerospace products are manufactured according to the AS9100-B standard, as dictated by our quality system.

Side View of Heat Pipes and HiK Plates Applied to Aircraft Electronics Assembly

Side Section View of Heat Pipes and HiK Plates Applied to a Typical Aircraft Electronics Assembly

Design and Fabrication:

ACT’s Aerospace Products team includes engineers that specialize in fluid and thermal sciences from a variety of disciplines, which include Aerospace, Chemical, Mechanical, and Nuclear Engineering. This unique combination of skill sets allows us to quickly and thoroughly understand thermal management issues and establish the optimum cooling solution to meet our customer’s needs.

We offer a wide range of services, such as feasibility studies, trade studies, design and analysis, product design, prototype manufacture and test, and full-scale, moderate-volume production. We use the most up-to-date design tools, including SolidWorks, ProE, CFDesign, Thermal Desktop and industry leading in-house performance prediction code.

Aircraft Electronics Study

Figure 1. Top Down Section View of Results from Aircraft Electronics Study. The left view shows the original temperature profile. The right view shows the temperature profile with ACT’s thermal management solution.

Analysis:

Recently, ACT completed an analytical and experimental study to develop an advanced thermal management system for an electronics enclosure used with fighter aircraft, including the F-35 Joint Strike Fighter (Anderson et al, 2010). The electronics enclosure in this study operated in a high temperature location and relied on liquid cooling to maintain component temperatures.

This approach turned out to be insufficient in hot environments, such as those encountered in the Middle East, and aircraft performance was restricted. Using passive thermal management technologies, which included heat pipes and HiK™ plates as illustrated in the side section view below, ACT was able to reduce the internal temperature gradient of the enclosure by 25 °C and alleviate the problem. Numerical results for this application are shown in figure 1. The experimental results matched numerical results very closely.

Dual Condenser Loop Heat Pipe Concept

Dual Condenser Loop Heat Pipe Concept

Test Results:

In a second part of this study, ACT developed and tested a dual-condenser Loop Heat Pipe (LHP) design to cool the liquid coolant prior to entering the enclosure. The dual condenser design allowed the LHP to interface with multiple sinks at different locations in the aircraft. Due to the nature of the LHP, the use of multiple sinks is essential for today’s aircraft due to the wide range of operating conditions they experience; a sink that is cool on the ground can rapidly heat up during flight and vice versa. The LHP designed by ACT was demonstrated to passively switch between heat sinks depending on their temperature. This allowed the LHP system to select the appropriate sink and prevent a high temperature sink from heating the liquid coolant. In addition to aircraft cooling, LHPs can be used for actuator cooling, and aircraft anti-icing.

Contact a member of our team to discuss how we can become your partner in commercial or military avionics thermal management.

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