





        BREAK1 USER INFORMATION (FORTRAN)

        1) INTRODUCTION

        BREAK1 is the Berkeley Algorithm for Breaking Window Glass in a
        Compartment Fire.  The program calculates the temperature history of
        a glass window for given fire parameters.  The calculations are
        stopped when the glass breaks.  The inputs required are the glass
        thermal conductivity, thermal diffusivity, absorption length,
        breaking stress, Young's modulus, thermal coefficient of linear
        expansion, thickness, emissivity, shading thickness, half-width of
        window, the ambient temperature, numerical parameters and the time
        histories of flame radiation from the fire, hot layer temperature
        and emissivity, and heat transfer coefficients.  The outputs are
        temperature history of the glass normal to the glass surface, and
        the window breakage time.  BREAK1 was written in FORTRAN by A. A.
        Joshi and P. J. Pagni, Department of Mechanical Engineering,
        University of California at Berkeley supported by a grant from the
        National Institute of Standards and Technology.   

        This disk contains the program executable (BREAK1.EXE) and source
        (BREAK1.FOR) files and sample data (INPUT1.DAT) and output
        (OUTPUT1.OUT) files for the BREAK1 program.  The user should refer
        to NIST-GCR-91-596, Users' Guide to BREAK1, the Berkeley Algorithm
        for Breaking Window Glass in a Compartment Fire, for complete
        information on using the program. 

        2) PROGRAM FILES

        An executable program file, BREAK1.EXE, is included on the disk.
        This file may be run directly on computers without a FORTRAN
        compiler.  It requires approximately 251K free random access memory
        and requires an 8087, 80287, or 80387 math coprocessor. 

        For users who wish to modify the program, the FORTRAN source code is
        included in file BREAK1.FOR.  All FORTRAN compilers are not the
        same.  As a result, this program may not compile with all versions
        of FORTRAN on the market.

        3) PROGRAM USE

        To run the program type BREAK1 followed by a carriage return.  If
        the program resides on a disk other than the designated drive then
        add the drive name, for example A:BREAK1.  The program prompts the
        user for inputs.  The inputs are case sensitive, meaning that if the
        program requests a "y" or "n" answer, these are not the same as "Y"
        and "N".  For the convenience of the user, Table I referenced in the
        program has been reproduced below.



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        BREAK1 Input values for normal glass

        Name                        Units   Format  Normal Range 

        Thermal conductivity        W/mK    E12.4   0.6-1.3
        Thermal diffusivity         m^2/s   E12.4   3.0-4.0 X 10^-7
        Absorption length           m       E12.4   0.9-1.5 X 10^-3
        Breaking stress             N/m^2   E12.4   2.0-13.8 X 10^7
        Young's modulus             N/m^2   E12.4   7.0-7.25 X 10^10
        Thermal coefficient
         of linear expansion        C^-1    E12.4   8.5-9.5 X 10^-6
        Thickness of glass          m       F8.4    0.1-3.0 X 10^-2
        Shading thickness           m       F8.4    0.3-5.0 X 10^-2
        Half-width of window        m       F8.4    0.05-5.0
        Heat transfer coefficient
         on exposed side            W/m^2K  F7.2    5.0-80.
        Heat transfer coefficient
         on unexposed side          W/m^2K  F7.2    3.0-20.
        Ambient temperature
         on unexposed side          K       F7.1    270.-320.
        Emissivity of glass         -       F6.2    0.8-1.0
        Emissivity of ambient       -       F6.2    0.1-1.0
        Emissivity of hot layer     -       F6.2    0.1-1.0
        Time                        s       F12.2   0.0-1500.
        Flame radiation flux        W/m^2   F12.2   0.0-10000.
        Hot layer temperature       K       F12.2   300.-1300.
        Time increment              s       F7.3    0.2-2.0
        Maximum error allowed
         in solutions               -       F10.6   10^-4 - 10^-2
        Maximum run time            -       F8.2    100.-1500.
        Output time interval        -       F7.2    1.0-100.

        4) SAMPLE DATA FILES

        A data input file based on the default case built into the program
        is included as INPUT1.DAT and the output file created by running
        this case is included as OUTPUT1.OUT.

        Exposed T is the glass temperature of the side exposed to the fire,
        Unexposed T is the temperature of the side of the glass away from
        the fire, Theta (average is the dimensionless average temperature
        obtained approximately as 1/2(theta(0)+theta(1))*erf(sqrt(tau)). 
        Tau is the dimensionless time, tau = t/tc, t is the time and tc is
        the characteristic time.  Avg. theta is average dimensionless
        temperature, theta = (Tav-Ti)/Tc, Tav is the average temperature, Ti
        is the initial temperature and Tc is the characteristic temperature. 
        G is the compression factor.  Avg. T init is the average initial
        temperature, Avg. Delta T is the average temperature increase.  Avg.
        T break is the average temperature at breakage. 


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        5) REVISION HISTORY

        5.1) DISKB01  initial release  BREAK1 Version 1.0 09/91


















































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