Structural firefighters can receive second-degree burns while working in thermal exposures considerably lower than flashover conditions. These exposures are usually several minutes in duration, and the exposure levels are generally not sufficient to degrade the turnout shell fabric. There is considerable interest in the role played by moisture, absorbed by clothing materials exposed to perspiration from a sweating firefighter, in burn injuries received in these conditions. Recent studies have shown that moisture, present in firefighter turnout systems, has a complex influence on heat transmission and potential for skin burn injuries [1,2]. At the same time, there is significant current interest in developing laboratory thermal protective performance testing protocols that incorporate reliable and realistic moisture preconditioning procedures. This paper describes an analysis of the effects of moisture on the thermal protective performance of turnout systems exposed to a low-level heat source. Sweat Absorption in Firefighter TurnoutsDuring fire fighting, firefighters 1 can sweat profusely causing moisture to accumulate in their turnout garments. This accumulated moisture can affect the ability of the turnout clothing materials to protect against prolonged exposure to heat in a structural fire within a room that has not reached flashover condition. This research was conducted to study the effects of moisture on the thermal protective performance of firefighter turnout materials in this type of radiant heat environment.Abstract This paper describes research on the effects of absorbed moisture on the thermal protective performance of the fire fighter turnout materials exposed to thermal assaults lower than flashover conditions. A thermal testing platform and sensor are used to measure thermal protective performance of turnout systems exposed to a sub flashover heat flux range 6.3 kw/m 2 (0.15 cal/ cm 2 s). The effects of moisture level on predicted second-degree burn injury for turnout systems having different moisture vapor permeability and total heat loss are discussed. Heat transfer analysis and experimental results show that, for selected test conditions, moisture negatively impacts protective performance most severely when the amount of added moisture is at a comparatively low level (15-20% of turnout system weight).

This research developes a numerical model to predict skin burn injury resulting from heat transfer through a protective garment worn by an instrumented manikin exposed to laboratory-controlled flash fire exposures. This model incorporates characteristics of the simulated flash fire generated in the chamber and the heat-induced changes in fabric thermophysical properties. The model also accounts for clothing air layers between the garment and the manikin. The model is validated using an instrumented manikin fire test system. Results from the numerical model help contribute to a better understanding of the heat transfer process in protective garments exposed to intense flash fires, and to establishing systematic methods for engineering materials and garments to produce optimum thermal protective performance.

From theoretical considerations, a custom slug calorimeter heat flux transducer was developed for experimental use in the measurement of heat fluxes transferred through layers of fabric to the surface of a human mannequin during simulated flash fire conditions. This paper describes the determination of the transducer's physical size, its limitations and heat loss considerations, a computer simulation of transducer operation and the evaluation of transient heat flux measurements. The transducer's loss factors were predicted numerically and determined experimentally. The overall performance of the transducer was also examined under varying simulated applied heat flux input.

This paper addresses some of the practical applications, advantages and difficulties associated with the engineering applications of virtual reality. The paper tracks actual investigative work in progress on this subject at the BNR research lab in RTl NC. This work attempts to demonstrate the actual value added to the engineering process by using existing 3-D CAD data for interactive information navigation and evaluation of design concepts and products. Specifically, the work includes iranslation of Parametric Technology's ProIENGINEER models into a virtual world to evaluate potential attributes such as multiple concept exploration and product installation assessment. Other work discussed in this paper includes extensive evaluation of two new tools, VRML and SGI's/Template Graphics' WebSpace for navigation through ProIENGINEER models with links to supporting technical documentation and data. The benefits of using these tools for 3-D interactive navigation and exploration throughout three key phases of the physical design process is discussed in depth. The three phases are Design Concept Development, Product Design Evaluation and Product Design Networking. The predicted values added include reduced time to "concept ready", reduced prototype iterations, increased "design readiness" and shorter manufacturing introduction cycles.

An established numerical model of a manikin fire test, which has the capability of predicting heat transfer through thermally protective clothing exposed to an intense heat environment, is described in this paper. The model considers the fire characteristics simulated in a manikin chamber as well as the insulating air layers between protective garments and the skin surface. The numerical model is applied to analyze the effects of simulated flash fire and variations in a skin model on a manikin test. The study demonstrates that the heat flux measured by 122 thermal sensors over the surface of the manikin exhibits a bell-shaped Gaussian distribution for a short duration in calibration burn. A series of flash fire data with different distributions was generated statistically, and the effects on burn predictions were investigated. The results suggest that the fire distribution affects the burn predictions for 4 s of exposure. The effects of initial temperature distribution, thermal properties, as well as involvement of blood perfusion in a skin model on burn predictions are also discussed. The model predictions demonstrate that the initial temperature distribution in a skin model has a large effect on burn predictions for a one-layer garment exposed to short duration flash fire conditions.