Estimation of Stirling engine regenerator on the analogy of laminar oscillating flow in a circular pipe
- LG Electronics Inc., Seoul (Korea, Republic of)
- Korea Inst. of Science and Technology, Seoul (Korea, Republic of)
- Seoul National Univ. (Korea, Republic of)
To design effective Stirling or other similar regenerative cycle machines, it is important to understand the heat transfer mechanism in the heat exchangers, especially in essential parts such as a regenerator. Most of the solutions for engineering were modelled under the assumption of an unidirectional steady flow; that is, during the first half of the regenerative cycle it flows in one direction with constant mass flow rate and during the second half of the cycle it flows in the other direction with the same mass flow rate. But its usefulness is limited by the available heat transfer data. Therefore, indirect experimental methods have been carried out for finding the Nusselt number. The basic idea of this method is to utilize two simple mathematical relations regarding regenerator effectiveness: one is expressed as a function of fluid inlet and outlet temperatures at both ends of the regenerator, and the other is expressed in the NTU (Number of Transfer Unit) number which is a function of mass flow rate, heat capacity and Nusselt number. Therefore, if one measures transient temperatures of the working fluid at both ends of the regenerator, it is possible to get the Nusselt number, and with these one can estimate effectiveness of the regenerator. However, the expression between regenerator effectiveness and NTU number is, in principle, applicable only to a classical counterflow heat exchanger composed of two unidirectional steady flows. The effect of oscillating flow characteristics, such as oscillation length and oscillation frequency, on the effectiveness of the regenerator has been neglected so far. By modelling a heat exchanger system (heater, cooler and regenerator) simply as an straight tube with specified boundary conditions, this paper analyzes the effect of oscillation length and frequency on the performance of the regenerator, and reviews the classical regenerator estimation method.
- OSTI ID:
- 170422
- Report Number(s):
- CONF-950729-; TRN: IM9605%%441
- Resource Relation:
- Conference: 30. intersociety energy conversion engineering conference, Orlando, FL (United States), 30 Jul - 5 Aug 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the 30. intersociety energy conversion engineering conference. Volume 3; Goswami, D.Y. [ed.] [Univ. of Florida, Gainesville, FL (United States)]; Kannberg, L.D.; Somasundaram, S. [eds.] [Pacific Northwest Lab., Richland, WA (United States)]; Mancini, T.R. [ed.] [Sandia National Labs., Albuquerque, NM (United States)]; PB: 493 p.
- Country of Publication:
- United States
- Language:
- English
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