Microvascular Materials for Active Cooling

PARTICIPANTS: ALEJANDRO ARAGON (PHD), SOHEIL SOGHRATI (PHD), PROF. ARMANDO DUARTE (U. ILLINOIS), PROF. SCOTT WHITE (U. ILLINOIS) AND PROF. PHILIPPE GEUBELLE

SUPPORT: AFOSR MURI

PROJECT DESCRIPTION: In this project, we combine a generalized finite element method developed in-house with a multi-objective/constraint genetic optimization scheme to perform the computational design of biomimetic microvascular materials with active cooling capabilities. At the heart of the problem is the ability to model in an accurate and efficient fashion the cooling effect created by complex network of microchannels embedded in a polymeric component subjected to a variety of thermal loading. Objective functions include the flow efficiency and void volume fraction associated with the microvascular network, and the maximum temperature obtained in the thermally loaded domain. CURRENT EMPHASIS IS PLACED IN INCORPORATING THS TECHNOLOGY IN A 3D FIBER-REINFORCED COMPOSITE TO BE USED FOR HIGH TEMPERATURE APPLICATIONS. THE CHALLENGE HERE CONSISTS IN COMBINING THE PRESENCE OF THE MICROVASCULAR NETWORK WITH THE COMPLEX MICROSTRUCTURE OF THE COMPOSITE AND TO INVESTIGATE THE IMPACT OF THE EMBEDDED NETWORK ON THE THERMAL AND STRUCTURAL RESPONSE OF THE COMPOSITE.

THIS FIGURE ILLUSTRATES THE EFFECT OF AN EMBEDDED HIERARCHICAL NETWORK ON THE TEMPERATURE FIELD OF AN ACTIVELY COOLED COMPONENT. THE LEFT FIGURE SHOWS THE TEMPERATURE DISTRIBUTION IN THE ABSENCE OF THE MICROVASCULAR NETWORK, WITH THE THERMAL LOADING ASSOCIATED WITH AN IMPOSED HEAT FLUX ON THE RIGHT SIDE OF THE DOMAIN. THE FIGURE ON THE RIGHT SHOWS HOW THE PRESENCE OF AN EMBEDDED NETWORK (WITH A MASS FLOW RATE OF 20 GRAMS PER MINUTE) AFFECTS THE TEMPERATURE DISTRIBUTION. THE THERMAL SOLUTION WAS OBTAINED USING A SPECIALLY DEVELOPED GENERALIZED FINITE ELEMENT SCHEME (ARAGON ET AL., IJNME, 2009).

This figure illustrates the effect of an embedded hierarchical network on the temperature field of an actively cooled component. The left figure shows the temperature distribution in the absence of the microvascular network, with the thermal loading associated with an imposed heat flux on the right side of the domain. The figure on the right shows how the presence of an embedded network (with a mass flow rate of 20 grams per minute) affects the temperature distribution. The thermal solution was obtained using a specially developed generalized finite element scheme (aragon et al., ijnme, 2009).

RELATED PUBLICATIONS:

  1. Aragón, A. M., Wayer, J. K., Geubelle, P. H., Goldberg, D. E. and White, S. R. (2008) “Design of microvascular flow networks using multi-objective genetic algorithms”. Comp. Methods Applied Mech. Eng., 197, 4399-4410. DOI: 10.1016/j.cma.2008.05.025.
  2. Aragón, A. M., Hansen, C. J., Wu, W., Geubelle, P. H., Lewis, J. and White, S. R. “Computational design and optimization of a biomimetic self healing/cooling  material.” In Behavior and Mechanics of Multifunctional and Composite Materials 2007, Edited by M. J. Dapino. Proceedings of SPIE, 6526. San Diego, CA, March 2007.
  3. Olugebefola, S. C., Aragón, A. M., Hansen, C. J., Hamilton, A. R., Kozola, B. D., Geubelle, P. H., Lewis, J. A., Sottos, N. R., and White, S. R. (2009) “Polymer-microvascular network composites.” To appear in J. Composite Materials.
  4. Wu, W., Hansen, C.L., Aragón, A.M., Geubelle, P.H., White, S.R. and Lewis, J.A. (2009) “Direct-write assembly of biomimetic microvascular networks for efficient fluid transport.” To appear in Soft Matter Communication.
  5. Aragón, A. M., Duarte, C. A. and Geubelle, P. H. (2009) “Generalized finite element enrichment functions for discontinuous gradient fields”.  IJNME. DOI: 10.1002/nme.2772.