On the effect of friction in steady flow of dense gases in pipes

✍ Scribed by D. Stojkovic; V.D. Djordjevic; P.S. Cvijanovic

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 203 KB
• Volume: 22
• Category: Article
• ISSN: 0142-727X
• DOI: 10.1016/s0142-727x(00)00077-1

✦ Synopsis

The eect of friction in steady, one-dimensional ¯ow of a real gas in pipes is treated in the paper, with an emphasis on the dense gas eects. In addition to the well-known fundamental derivative of gas-dynamics C, another derivative, de®ned as C 1 1 q oc=oq T =c; is shown to play a very important role in studying these non-isentropic ¯ows. In both of two characteristic cases of ¯ow, isothermal and adiabatic one, pressure and density variations along the pipe are not aected by the dense gas eect, their variations being qualitatively the same as in perfect gas theory. Variations of the temperature and of the Mach number are, however, severely in¯uenced by the dense gas eect. Perhaps the most important result from the practical point of view is that isothermal ¯ow in the C 1 < 0 region is choking-free, and that adiabatic ¯ow in the C < 0 is almost choking-free. Analytic considerations derived in the paper are supported by a number of numerical results for a van der Waals gas.