Search Results

Electrohydrodynamic (EHD) forces acting on a fluid can be used to significantly increase the heat transfer coefficient with little power consumption or flow restriction. Experiments have shown promising results with simple configurations, but practical heat exchanger development is needed. Analytical development will establish design equations and aid in experimental data correlation. Small scale test units will provide experience in determining heat exchanger configurations and electrode options. Controller and high voltage power supply units will also need to be developed. Full-scale EHD heat exchanger systems can then be developed to demonstrate technology availability for military and commercial products.

Vapor cycle refrigeration units are being developed for expanded applications on aircraft and future spacecraft. These units offer advantages in high efficiency, closed system operation, high flux cooling, close temperature control, and long-term dependability. This paper provides an overview of approaches to vapor cycle compressor design for achieving high reliability and long life. Different types of compressors are reviewed, and descriptions are given for new innovations such as magnetic bearings, variable speed motors, and magnetic couplings.

The Air Force has an initiative entitled, Subsystem Integration Technology (SUIT) to develop and demonstrate integration technology as applied to the traditional aircraft utility subsystems. Utility subsystems perform functions such as auxiliary power generation, environmental control, and fuel management. Commonly these different subsystems are developed independently and then interfaced when building a particular flight vehicle. The SUIT program considers all functions accomplished by the traditional utility subsystems to be responsibilities of a single entity called a utility suite. This suite is designed with overall vehicle level performance objectives rather than trying to maximize the performance of individual functions and is not bound to maintaining the traditional allocation of functions among the hardware labeled as fuel management, environmental control, or secondary power.