Determination of dividing streamline heights and Froude numbers for predicting plume transport in complex terrain
The use of the local Froude number to obtain the critical streamline dividing height of flow encountering an isolated terrain feature has certain limitations when applied to complicated atmospheric conditions. In cases with a uniform density gradient and constant flow speed a single hill Froude number can be calculated and used to determine the dividing streamline height directly. In flow field composed of distinct layers, a local Froude number can be calculated for each layer. This in turn provides a dividing height above the base of the layer of interest. In order to consider the conditions encompassing the entire hill, an alternate method may be used where the relationship between kinetic energy in the approach flow and the potential energy gained as an air parcel is lifted over the hill is solved iterativley for the dividing streamline height. While the iterative approach yields a height which properly accounts for the ratio of inertial and gravitational forces, the local Froude number method is a simpler, quicker method for approximating the critical dividing streamline height. Results indicate that both methods yield generally correct guidelines of plume behavior.
- Research Organization:
- Washington State Univ., Pullman
- OSTI ID:
- 7099381
- Journal Information:
- J. Air Pollut. Control Assoc.; (United States), Vol. 34:2
- Country of Publication:
- United States
- Language:
- English
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