DOI QR코드

DOI QR Code

시간에 대해 감속하는 난류 파이프 유동에 관한 연구

Turbulence in temporally decelerating pipe flows

  • 투고 : 2016.03.30
  • 심사 : 2016.04.16
  • 발행 : 2016.04.30

초록

Direct numerical simulations (DNSs) of turbulent pipe flows with temporal deceleration were performed to examine response of the turbulent flows to the deceleration. The simulations were started with a fully-developed turbulent pipe flow at the Reynolds number, $Re_D=24380$, based on the pipe radius and the laminar centerline velocity, and three different constant temporal decelerations were applied to the initial flow with varying dU/dt = -0.001274, -0.00625 and -0.025. It was shown that the mean flows were greatly affected by temporal decelerations with downward shift of log law, and turbulent intensities were increased in particular in the outer layer, compared to steady flows at a similar Reynolds number. The analysis of Reynolds shear stress showed that second- and fourth-quadrant Reynolds shear stresses were increased with the decelerations, and the increase of the turbulence was attributed to enhancement of outer turbulent vortical structures by the temporal decelerations.

키워드

참고문헌

  1. Mizushina, T., Maruyama, T., Shiozaki, Y., 1973, "Pulsating turbulent flow in a tube," J. Chemical Engineering Japan., vol.6, pp.487-494.
  2. Ramaprian, B.R., Tu, S.W., 1983, "Fully developed periodic turbulent pipe flow. Part 2: The detailed structure of the flow.," J. Fluid Mech., vol.137, pp.59-81. https://doi.org/10.1017/S0022112083002293
  3. Shemer, L., Wygnanski, I., Kit, E., 1985. "Pulsating flow in a tube," J. Fluid Mech., vol.153, pp.313-337. https://doi.org/10.1017/S0022112085001276
  4. Tardu, S.F., Binder, G., Blackwelder, R.F., 1994. "Turbulent channel flow with large amplitude," J. Fluid Mech., vol.267, pp.109-151. https://doi.org/10.1017/S0022112094001138
  5. Scotti, A., Piomelli, U., 2001. "Numerical simulation of pulsating turbulent channel flow," Phys. Fluids., vol.13, pp.1367-1384. https://doi.org/10.1063/1.1359766
  6. Scotti, A., Piomelli, U., 2002. "Turbulence models in pulsating flows," AIAA Journal., vol.40, pp.537-543. https://doi.org/10.2514/2.1679
  7. Kataoka, K., Kawabata, T., Miki, K., 1975. "The start-up response of pipe flow to a step change in flow rate," J. Chemical Engineering Japan., vol.8 (4), pp.266-271. https://doi.org/10.1252/jcej.8.266
  8. Maruyama, T., Kuribayashi, T., Mizushina, T., 1976. "The structure of the turbulence in transient flows," J. Chemical Engineering Japan., vol.9, pp.431-439. https://doi.org/10.1252/jcej.9.431
  9. He, S., Jackson, J.D., 2000. "A study of turbulence under conditions of transient flow in a pipe," J. Fluid Mech., vol.408, pp.1-38. https://doi.org/10.1017/S0022112099007016
  10. Greenblatt, D., Moss, E.A., 2004. "Rapid temporal acceleration of a turbulent pipe flow," J. Fluid Mech., vol.514, pp.65-75. https://doi.org/10.1017/S0022112004000114
  11. Jung S.Y., Chung Y.M., 2012. "Large-Eddy simulation of accelerated turbulent flow in a circular pipe," Int. J. Heat and Fluid Flow., vol.33, pp.1-8. https://doi.org/10.1016/j.ijheatfluidflow.2011.11.005
  12. Nagano, Y., Tagawa, M., Tsuji, T., 1993. "Effects of adverse pressure gradients on mean flows and turbulence statistics in a boundary layer," In: Durst, F., Friedrich, R., Launder, B.E., Schmidt, F.W., Schumann, U., Whitelaw, J.H. (Eds.), Turbulent Shear Flows, vol.8, Springer, Berlin, pp.7-21.
  13. Kim, K., Baek, S.-J., Sung, H.J., 2002. "An implicit velocity decoupling procedure for the incompressible Navier-Stokes equations," Int. J. for Numerical Methods in Fluids., vol.38 (2), pp.125-138. https://doi.org/10.1002/fld.205
  14. Lee J.H., Sung H.J., 2008. "Effects of an adverse pressure gradient on a turbulent boundary layer," Int. J. Heat and Fluid Flow., vol.29, pp.568-578. https://doi.org/10.1016/j.ijheatfluidflow.2008.01.016
  15. Robinson, S.K., 1991. "Coherent motions in the turbulent boundary layer," Ann. Rev. Fluid Mech., vol.23, pp.601-639. https://doi.org/10.1146/annurev.fl.23.010191.003125