Compartment fire near-field entrainment measurements

Abstract A widely accepted consensus on entrainment models for large fires in compartments does not yet exist. To obtain further information on such entrainment rates, 20 full-scale, near-field experiments were conducted. Near-field entrainment occurs when hot layer interface heights are beneath the burner mean flame height so that cold layer entrainment occurs only near the burner surface. A durable compartment, similar to the standard fire test compartment, was designed and used in conjunction with a 0·61 m × 1·22 m porous surface propane burner to produce compartment fires with heat release rates from 330 to 980 kW. Entrainment rates of 0·74–0·98 kg/s were calculated from temperature measurements made within the compartment and in the doorway. The entrainment rates determined here were correlated with values from the literature. This correlation led to two curve fits which modify Zukoski's far-field offset model and can be used to estimate near-field entrainment rates. An offset for the near-field model of Thomas was also developed. The fire plume model of Baum and McCaffrey was found to compare favorably with the entrainment rates determined here.

[1]  Gary F. Bennett,et al.  The SFPE handbook of fire protection engineering : By P.J. DiNenno, C.L. Beyler, R.L.P. Custer, W.D. Walton and J.M. Watts, Jr., National Fire Protection Association, Quincy, MA and Society of Fire Prot , 1990 .

[2]  R. Chitty,et al.  Some Source-Dependent effects of unbounded fires , 1985 .

[3]  James G. Quintiere,et al.  Growth of Fire in Building Compartments , 1976 .

[4]  E. E. Zukoski,et al.  Mass Flux In Fire Plumes , 1994 .

[5]  B. Mccaffrey.  Purely buoyant diffusion flames :: some experimental results , 1979 .

[6]  H. Bean,et al.  Fluid meters : their theory and application , 1971 .

[7]  Yuji Hasemi,et al.  Fuel Shape Effect on the Deterministic Properties of Turbulent Diffusion Flames , 1989 .

[8]  James Henry Morehart.  Species produced in fires burning in two-layered and homogenous vitiated environments , 1991 .

[9]  P. H. Thomas,et al.  Testing Products and Materials for Their Contribution to Flashover in Rooms , 1981 .

[10]  Paul A. Reneke,et al.  A User's Guide for CFAST Version 1.6 , 1992 .

[11]  J. S. Newman,et al.  Simple Aspirated Thermocouple for Use in Fires , 1979 .

[12]  Howard R. Baum,et al.  Fire Induced Flow Field - Theory And Experiment , 1989 .

[13]  Christopher S. Lim,et al.  I. Mixing in doorway flows. II. Entrainment in fire plumes , 1984 .

[14]  John A. Rockett,et al.  Fire Induced Gas Flow in an Enclosure , 1976 .

[15]  S. Toner,et al.  Entrainment, Chemistry, and Structure of Fire Plumes , 1987 .

[16]  James G. Quintiere,et al.  An Assessment of Fire Induced Flows in Compartments , 1984 .

[17]  Gunnar Heskestad,et al.  Fire plume air entrainment according to two competing assumptions , 1988 .

[18]  Vytenis Babrauskas,et al.  Upholstered Furniture Room Fires—Measurements, Comparison With Furniture Calorimeter Data, and Flashover Predictions , 1984 .

[19]  James G. Quintiere,et al.  Flow induced by fire in a compartment , 1982 .

[20]  L. K. Spink.  Principles and Practice of Flow Meter Engineering , 1939 .

[21]  Takeyoshi Tanaka,et al.  Doorway flow induced by a propane fire , 1986 .

[22]  B. Mccaffrey.  Momentum implications for buoyant diffusion flames , 1983 .

[23]  Craig L. Beyler,et al.  Fire plumes and ceiling jets , 1986 .

[24]  Edward E. Zukoski,et al.  Entrainment in the Near and Far Field of Fire Plumes , 1984 .

[25]  P. L. Hinkley.  Rates of 'production' of hot gases in roof venting experiments , 1986 .

[26]  Yuji Hasemi,et al.  Flame Geometry Effects on the Buoyant Plumes from Turbulent Diffusion Flames , 1984 .

[27]  J. C. Jaeger,et al.  Conduction of Heat in Solids , 1952 .

[28]  W. Parker,et al.  Calculations of the Heat Release Rate by Oxygen Consumption for Various Applications , 1982 .

[29]  P. H. Thomas,et al.  Buoyant diffusion flames: Some measurements of air entrainment, heat transfer, and flame merging , 1964 .

[30]  M. Delichatsios.  Procedure for Calculating the Air Entrainment Into Turbulent Pool and Jet Fires , 1990 .