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Parameterization of the Johnson & Ettinger Model



In the publication Identification of Critical Parameters for the Johnson and Ettinger (1991) Vapor Intrusion Model, (American Petroleum Institute Technical Bulletin Number 17, 2002), Paul Johnson writes the Johnson and Ettinger (1991) algorithm in terms of three dimensionless parameters:



where







Each of these parameters has a physical relevance, and by analyzing the value of these parameters for a given set of inputs, insight can be gained about vapor transport through the system.

A brief description of this process is given below and the user is directed to Paul Johnson's paper for more detailed information.

If B < 0.1 &#8594 Diffusion is the dominant mechanism across the foundation.

If B > 3 &#8594 Advection is the dominant mechanism across the foundation.

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