Iso-grid, Thermal-Structural Panel (IsoTherm)

PI: Hans-Peter Dumm, Air Force Research Laboratory - Kirtland

Due to current industry trends in electronics component design and packaging, spacecraft are becoming smaller and more powerful. As a result, spacecraft power densities are foreseen to increase dramatically in the coming years, and thermal considerations are expected to become an even larger problem than on current spacecraft. Today’s thermal control technologies will soon be too inefficient or ineffective to meet tomorrow’s needs, and innovative thermal management solutions are required to ensure that thermal considerations do not limit spacecraft capabilities on future missions. This project presents a revolutionary new thermal control solution in development at the Air Force Research Laboratory (AFRL) Space Vehicles Directorate, called IsoTherm, which provides a 100X increase in thermal performance by integrating a two-phase (liquid/vapor) cooling loop within the ribs of an isogrid structural panel, with no detrimental effect on the stiffness/mass ratio of the panel. The objective of our experiment is to quantify the performance of the IsoTherm system, and the electrohydrodynamic (EHD) pumps that power it, in a microgravity environment.

Work continues under T0091-P.

Technology Areas (?)
  • TA14 Thermal Management Systems
Problem Statement

The IsoTherm concept was inspired by the circulatory system of biological organisms, which is highly efficient and provides multiple functions within one system, including thermal regulation, oxygen flow, and constituents for self-healing. By adapting this multi-functional architecture to the structural panels of a satellite bus, impressive performance improvements may be realized. While several studies have been conducted showing that electrohydrodynamic (EHD) pumps can operate effectively in two-phase applications, all were conducted in 1g environments. It is well known that the behavior of two-phase flows is quite different in microgravity, and this will affect the performance of the EHD pump. A thorough characterization of IsoTherm is necessary for optimization of the current system and to design future generations of two-phase multifunctional structures.

Technology Maturation

The anticipated outcome of the experiment is a better understanding of how microgravity will affect the performance of IsoTherm. This includes the effects on the power required for an EHD pump to deliver a desired flow rate and pressure head, the change in heat transfer coefficient between the IsoTherm channels and an electronic component that needs to be cooled, the maximum heat flux IsoTherm is capable of dissipating, and the power required to operate IsoTherm as a function of applied heat loa

Future Customers

IsoTherm is an adaptable, cross-cutting technology that can be applied to all high-power spacecraft, cutting weight and increasing power capabilities for nearly all future missions.

Flight Experiment Objectives

The experiment requires near-zero gravity conditions. Three minutes of microgravity are necessary to achieve the test objectives, requiring approximately 10 parabolas. Three people are required for the experiment: one to operate the panel, one to collect data on pump performance, and the third to collect data regarding the panel performance.

Technology Details

  • Selection Date
    AFO1 (May 2011)
  • Program Status
  • Current TRL (?)
    TRL 5
    Successful FOP Flights
  • 1 Parabolic

Development Team

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