Dragon Breath, Phase II

Abstract

The current NSW dry suit loses approximately 200W of heat by conduction to 0 C water. The heat loss causes hypothermia within as little as two hours in 40 F water. Sixteen additional Watts of heat is lost due to breathing alone. Losses exceed 32 W under exertion." For comparison , the total body head generated by an adult male is only 80 W at rest. Rebreathers currently wast 100% of respirator"y heat because they are worn outside the body. Respiratory heat lossess have two primarily components: convective and evaporative. Convective heat losses occur when inhaling cold air. They are only about 3 W since air requires comparatively little heat to rise in" temperature. More important is the loss of heat due to the evaporation of water. At 10 C and 25% relative humidity, evaporative los"ses are approximately 13 W. JHU/APL therefore proposes the development of a CO2 scrubber that is worn as a vest inside the dry suit". As a component of a rebreather, the novel CO2 scrubber passively heats the diver in cold environments. By eliminating convective" heating loss and generating exotherms from CO2 and H2 O capture the vest will met a minimum of 30W of heat to the diver. The value is approximately doubles under exertion. The passive heating from Dragon Breath will reduce the need for bulky active heating sources or it could extend the duration of the mission

Document Details

Document Type
DoD Grant Award
Publication Date
Sep 01, 2017
Source ID
N000141712812

Entities

People

  • Jason J Benkoski

Organizations

  • Johns Hopkins University
  • Office of Naval Research
  • United States Navy

Tags

Readers

  • Materials Science
  • Thermal Physics or Thermal Science.