Measuring mass loss rates in free burning fires

Accurate data on mass loss rates of fuels in large, free-burning fires are scant. However, the authors report a method of making such measurements, which, when tested, provided reliable data. Note: Mr. Murray is now in the Forestry and Timber Bureau, Canberra, Australia; Mr. Northcutt is now in the Division of Forest Fire and Atmosphere Research, Forest Service, USDA, Washington, D. C.; and Mr. Countryman is stationed at Riverside, California.     

A high temperature water-cooled anemometer

Prior attempts to measure air velocity within and near fires have not been completely successful because of mechanical and electronic failures due to heat. A system of cooling critical mechanical and electronic parts of anemometers using liquids has been developed to overcome this problem. Note: Mr. Palmer is stationed at Riverside, California, and Mr. Northcutt’s current address is Division of Forest Fire and Atmospheric Sciences Research, Forest Service, U.S. Department of Agriculture, Washington, D.C. 20250.     

Effect of fire whirlwind formation on solid fuel burning rates

Burning rates of Douglas fir wood were measured using crosspiled sticks 1/4, 1/2, 3/4, and 1 in. (0.64, 1.27, 1.90, and 2.54 cm) in cross-sectional dimensions. Burning was 1.4 to 4.2 times as fast with the whirlwind as without. Note: Mr. Martin is Project Leader, Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture, and Professor, College of Forest Resources, University of Washington. Mr. Pendleton is a Forester, Forest Service, U.S. Department of Agriculture, Leavenworth, Washington. Mr. Burgess is a Forester, Pack River Forest Products, Peshastin, Washington. This paper was presented at the Combustion Institute, Western States Section at Pullman, Washington, May 6–7, 1974.     

Application of CMA program to wood charring

Experiments were conducted to test the ability of a computer program to describe the charring of ovendried wood. Note: Mr. White is a Forest Products Technologist and Dr. Schaffer is a Supervisory Research Engineer at the Forest Service's Forest Products Laboratory. The Laboratory is maintained at Madison, Wisconsin in cooperation with the University of Wisconsin. Note: The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute official endorsement or approval by the U.S. Department of Agriculture of any product or service to the exclusion of others that may be suitable.     

Model experiment of hazardous forest fire whirl

The fluid dynamical scaling laws of forest fires are derived by dimensional analysis and a scale model is constructed to investigate a forest fire which seriously injured several fire fighters. The result of the small-scale experiment indicate that a fire whirl could be generated in such a fire. Note: Mr. Richard I. Emori is with the Mechanical Engineering Department, Seikei University, 3-Kichijoji Kitamachi, Musashino, Tokyo, Japan. Mr. Kozo Saito is a Research Associate with the Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey.     

A fire danger rating system for Hawaii

Extremes in rainfall on the Hawaiian Islands make it difficult to judge forest fire danger conditions. The use of an automatic data collection and computer processing system helps to monitor the problem. Note: Messrs. Burgan and Fujioka are on the staff of the Pacific Southwest Forest and Range Experiment Station, Forest Service, U. S. Department of Agriculture. Mr. Hirata is with the National Weather Service. All three are stationed at Honolulu, Hawaii.     

A portable IR system for observing fire thru smoke

A comparatively recent development in electronic technology holds promise for providing a practical means for locating and following the progress of forest fires. Early tests indicate that a prototype system has advantages and a sensitivity that surpass conventional television systems. Note: Mr. Maxwell is stationed at Riverside, California.     

A new test method for automatic fire detection devices

A new test method is proposed in which all automatic fire detectors, regardless of sensor type, would be subjected to a series of the same test fires. Note: Mr. Bright presented this paper at the 80th Annual Meeting of the National Fire Protection Association in Houston, Texas, May 1976.     

Occurrences of lightning fires — Can they be simulated?

A computer simulation model of lightning fire discoveries has been developed by analyzing historical records of lightning fire occurrences. The model is being tested by using reports of lightning fires from four national forests. Results to date suggest that statistical distributions can be used to model the characteristics of lightning fire discoveries. Note: The author is stationed at the Pacific Southwest Forest and Range Experiment Station, Station, Riverside, California.     

The effect of humidity,air temperature,and wind speed on fine fuel moisture content

A controlled environmental chamber was used to study the effects of relative humidity, air temperature, and wind speed on moisture content of tobosa grass. Prediction equations were developed to show rates of change in fine fuel moisture content and equilibrium fine fuel moisture content for both absorption and desorption. Note: Mr. Britton is a Research Associate at Texas Tech University; Mr. Countryman, a Project Leader, Forest Fire Laboratory, Riverside, California; Dr. Wright, Associate Professor of Range Management, Texas Tech University; and Dr. Walvekar, Associate Professor of Industrial Engineering, Texas Tech University. Mr. Britton’s current address is Range Science Department, Texas A & M University, College Station, Texas. Note: This paper is College of Agricultural Sciences, Texas Tech University Contribution No. T-9-111.     

Development of halogenated hydrocarbon foam (halofoam) extinguishants

The authors report on a study in which a number of halogenated hydrocarbon foams were developed, which are more effective than bromochloromethane in extinguishing Types A, B, and C fires. Note: This paper is a summary of a report by the same title, No. AFAPL-TR-71-21, prepared by Arthur D. Little, Inc. for Wright-Patterson Air Force Base, Ohio, April 1971. A patent application was field with the United States Patent Office on April 29, 1971. Mr. Atallah’s presentation at the 75th Annual Meeting of the National Fire Protection Association on May 19, 1971 in San Francisco, California was also based on this report.     

The accumulation of gases on an upper floor during fire buildup

Full-scale tests with rapidly developing and slowly developing fires were conducted in an effort to contribute to the understanding of the mechanisms of death by toxic gases in building fires. Note: Dr. Wagner’s present address is Department of Electrical Engineering, The Johns Hopkins University, Baltimore, Md. This work was supported by the National Science Foundation under Grant GI-12.     

Halon 1301 — Minimum concentrations for extinguishing deep-seated fires

Existing standards are rather specific about the concentrations of gaseous extinguishing agents needed to extinguish Class B fires. Such is not the case with Class A fires. The author reports the results of tests to support his contention that extinguishment requirements for common solid materials can be determined. Note: Presented at the 76th Annual Meeting of the National Fire Protection Association, May 17, 1972, Philadelphia, Pa.     

A new fire management policy on Forest Service lands

A new Forest Service policy, effective February 1978, allows some wildfires to burn under prescribed conditions, urges a multidisciplinary approach to fire control, and has applications to rural and urban situations. Note: The author, formerly with the Pacific Southwest Forest and Range Experiment Station, Berkeley, Calif., is now with the Forest Fire and Atmospheric Sciences Research Staff, Washington, D.C.     

Extinguishment of natural gas pressure fires

Several series of tests have been performed to compare the effectiveness of sodium bicarbonate-base and potassium bicarbonate-base dry chemicals in extinguishing natural gas fires. The author describes the methods used to analyze test data and recommends specific dry chemical application rates for extinguishing such fires. Note: Copies of the motion picture records of the tests may be borrowed from The Ansul Company and the Safety First Products Corporation.     

The Ellis parkway and gary dwelling burns

The author reports on two full-scale experimental building fires, the results of which suggest that fire spread through a subdivided structure can be described as a series of predictable flashovers. IIT Research Institute Note: The experimental fires discussed in this paper were mentioned briefly in “Studies of Building Fires with Models,” F. Salzberg and T. E. Waterman,Fire Technology, Vol. 2, No. 3 (August 1966), p. 198.     

A fire station placement model

The authors have constructed an analytical model to solve the fire station placement problem. Quick and ready graphs have been prepared for its application by fire service personnel. Note: Mr. Guild is a member of the Department of Industrial Engineering, and Mr. Rollin is with the Ordnance Research Laboratory.     

Simulation of water mist suppression of small scale methanol liquid pool fires

The focus of this paper is on numerical modeling of methanol liquid pool fires and the suppression of these fires using water mist. A mathematical model is first developed to describe the evaporation and burning of liquid methanol. The complete set of unsteady, compressible Navier–Stokes equations are solved along with an Eulerian sectional water mist model. Heat transfer into the liquid pool and the metal container through conduction, convection and radiation are modeled by solving a modified form of the energy equation. Clausius–Clapeyron relationships are invoked to model the evaporation rate of a two-dimensional pool of pure liquid methanol.The interaction of water mist with pulsating fires stabilized above a liquid methanol pool and steady fires stabilized by a strong co-flowing air jet are simulated. Time-dependent heat release/absorption profiles indicate the location where the water droplets evaporate and absorb energy. The relative contribution of the various suppression mechanisms such as oxygen dilution, radiation and thermal cooling is investigated. Parametric studies are performed to determine the effect of mist density, injection velocity and droplet diameter on entrainment and suppression of pool fires. These results are reported in terms of reduction in peak temperature, effect on burning rate and changes in overall heat release rate. Numerical simulations indicate that small droplet diameters exhibit smaller characteristic time for decrease of relative velocity with respect to the gas phase, and therefore entrain more rapidly into the diffusion flame than larger droplet. Hence for the co-flow injection case, smaller diameter droplets produce maximum flame suppression for a fixed amount of water mist.     

Developing a cost-effective fire management plan for California’s Kern Plateau

The Kern Plateau in Sequoia National Forest was selected as a pilot study area for the development and application of a new fire management planning process. Note: Jason M. Greenlee is President of Fire and Land Management Enterprises (FLAME), Boulder Creek, California. Carl C. Wilson was formerly National Fire Specialist for the Forest Service, USDA, and is now a Forest Fire Consultant at Berkeley, California.     

Evaluating fire prevention effectiveness through a probability model

A probability model has been developed to evaluate the effectiveness of fire prevention efforts applied under specific weather conditions. Note: Bradley B. Nickey is assigned to the Pacific Southwest Forest and Range Experiment Station, Forest Service, U. S. Department of Agriculture. Clifford B. Chapman is with the Department of Forestry, State of California.