Engineering topics

Shia, Run-Lie

Publications and source records attributed to Shia, Run-Lie.

21 records · Page 2

NASA NTRS1991

Effects of engine emissions from high-speed civil transport aircraft: A two-dimensional modeling study, part 2

The AER two-dimensional chemistry-transport model is used to study the effect of supersonic and subsonic aircraft operation in the 2010 atmosphere on stratospheric ozone (O3). The results show that: (1) the calculated O3 response is smaller in the 2010 atmosphere compared to previous calculations performed in the 1980 atmosphere; (2) with the emissions provided, the calculated decrease in O3 column is less than 1 percent; and (3) the effect of model grid resolution on O3 response is small provided that the physics is not modified.

Ko, Malcolm K. W.↗

NASA NTRS1990

Two-dimensional atmospheric transport and chemistry model - Numerical experiments with a new advection algorithm

Extensive testing of the advective scheme proposed by Prather (1986) has been carried out in support of the California Institute of Technology-Jet Propulsion Laboratory two-dimensional model of the middle atmosphere. The original scheme is generalized to include higher-order moments. In addition, it is shown how well the scheme works in the presence of chemistry as well as eddy diffusion. Six types of numerical experiments including simple clock motion and pure advection in two dimensions have been investigated in detail. By comparison with analytic solutions, it is shown that the new algorithm can faithfully preserve concentration profiles, has essentially no numerical diffusion, and is superior to a typical fourth-order finite difference scheme.

Shia, Run-Lie↗

NASA NTRS1989

Sensitivity study of advection and diffusion coefficients in a two-dimensional stratospheric model using excess carbon 14 data

The time evolution of excess C-14 in the stratosphere and the troposphere from October 1963 to December 1966 is investigated using the Caltech/JPL two-dimensioanal transport model, with transport coefficients taken from Yang and Tung (1989). It is found that the model successfully accounts for observations reported previously. It is calculated that excess C-14 is removed from the atmosphere with surface deposition velocities of 0.003 cm/sec in the Southern Hemisphere and 0.005 cm/sec in the Northern Hemisphere. This result is contrary to the current understanding that the oceans are the dominant sink for excess C-14.

Shia, Run-Lie↗