Accession Number : ADA314791

Title :   The Effects of Wave Conditions on Dry Immersion Suit Insulation: A Comparison Between Humans and Manikin,

Corporate Author : DEFENCE AND CIVIL INST OF ENVIRONMENTAL MEDICINE DOWNSVIEW (ONTARIO)

Personal Author(s) : Ducharme, Michel B. ; Brooks, Christopher J.

PDF Url : ADA314791

Report Date : JUN 1996

Pagination or Media Count : 50

Abstract : The objective of the present study was to investigate the effect of standard wave conditions (0 to 70 cm) on dry immersion suit insulation when tested on humans and a manikin simultaneously. Six human subjects and a thermal manikin dressed with the same dry immersion suit system (pile undergarment insulation, uninsulated immersion suit and neoprene gloves and hood) were immersed simultaneously for one hour in 16 deg C water rendered turbulent with an irregular wave pattein. One immersion was performed for each randomly chosen wave condition, from 0 to 70 cm wave height, changing by steps of 10 cm. In addition to the physiological parameters measured on the human subjects (skin and rectal temperatures, skin heat loss and heart rate), and the ambient temperature of water and air, heat fluxes and surface temperatures were measured at 12 sites on the subjects and manikin for each compartment of the dry suit system (skin, pile garment, suit garment). This allowed the calculation of the thermal resistance of every suit compartment in addition to the air and water boundary layer surrounding the suit. The results showed that none of the physiological parameters were significantly affected by the wave conditions, except for the skin heat flux which increased with wave height from 72.0 +/- 1.9 W m(-2) at 0 cm to 85.5 +/- 2.9 W m(-2) at 70 cm. The thermal resistance data showed that wave height up to 70 cm decreased dry suit system insulation by 14 and 17% when measured on human subjects and manikin, respectively; and that the only suit component significantly affected by the wave motion was the insulation of the water and air boundary layers surrounding the body. The body sites that were the most affected by the effect of wave motion were the head, and the proximal limbs with a 58% and 63% decrement in suit thermal resistance from 0 to 70 cm wave height for humans and mani

Descriptors :   *SURFACE TEMPERATURE, *IMMERSION, *THERMAL RESISTANCE, TEST AND EVALUATION, TEMPERATURE, HUMANS, AIR, PARAMETERS, WATER, SITES, MOTION, BOUNDARY LAYER, PHYSIOLOGY, HEAT FLUX, HEART RATE, HEIGHT, WAVES, GLOVES, HEAT LOSS, MANNEQUINS, NEOPRENE, RECTUM.

Subject Categories : Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE