Exact peak capturing and oscillation-free scheme to solve advection-dispersion transport equations

Technical Report · Wed Jan 01 04:00:00 EST 1992

OSTI ID:6830516

Yeh, G T; Chang, J R; Short, T E

An exact peak capturing and essentially oscillation-free (EPCOF) algorithm, consisting of advection-dispersion decoupling, backward method of characteristics, forward node tracking, and adaptive local grid refinement, is developed to solve transport equations. The algorithm represents a refinement of LEZOOM, developed earlier by the senior author. In LEZOOM, a predetermined number of evenly spaced, hidden nodes was zoomed for a sharp front element, while in the EPCOF scheme, a subset of forwardly tracked nodes is zoomed. The number and location of the subset were automated. As a result, the peaks and valleys are captured exactly; and the ancillary problems of spurious oscillation, numerical dispersion, and phase errors are alleviated. Means of checking accumulated mass balance errors are provided. Application of the algorithm to two one-dimensional benchmark problems under a variety of conditions indicated that it completely eliminated peak clipping, spurious oscillation, phase error, and numerical dispersion. It yielded identical results, within the error tolerance, to exact solutions for all 19 test cases. Accumulated mass balance errors are extremely small for all 19 cases. The EPCOF scheme could solve the advective transport problems exactly, within any prescribed error tolerance, using mesh Peclet numbers ranging from 0 to infinity and very large mesh Courant numbers.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States). Dept. of Civil Engineering
• OSTI ID: 6830516
• Report Number(s): PB-93-131845/XAB; CNN: EPA-R-818322
• Country of Publication: United States
• Language: English

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ABSTRACTS
ADVECTION
ALGORITHMS
COMPUTER CALCULATIONS
DECOUPLING
DISPERSIONS
DOCUMENT TYPES
DYNAMICS
ELECTRODES
EQUATIONS
ERRORS
FLUID FLOW
GRIDS
GROUND WATER
HYDROGEN COMPOUNDS
HYDROLOGY
LEADING ABSTRACT
MASS TRANSFER
MATHEMATICAL LOGIC
MATHEMATICAL MODELS
MECHANICS
MIXTURES
OXYGEN COMPOUNDS
SOLUTIONS
TOLERANCE
TRANSPORT THEORY
WATER