ACADSTAFF UGM
| Title | : | Numerical study on the Effect of Working Gases on the Critical Temperature Difference of a Standing Wave Thermoacoustic Prime Mover |
| Author | : |
Ikhsan Setiawan, S.Si., M.Si. (1) Masafumi Katsuta (2) Makoto Nohtomi (3) |
| Date | : | 0 2013 |
| Keyword | : | Thermoacoustic prime mover, standing wave, critical temperature difference, working gases Thermoacoustic prime mover, standing wave, critical temperature difference, working gases |
| Abstract | : | Thermoacoustic prime movers (TAPM) are energy conversion devices which convert heat into acoustic work. Heat from various external sources such as waste heat and sunlight might be used to drive the devices. A minimum temperature difference across a stack in the prime mover is required to be able to produce acoustic work. Low critical temperature differences are desired when we intend to utilize low quality of heat sources. This paper describes a numerical study on the effect of working gases on the critical temperature difference (Tcrit) of a standing-wave TAPM. We considered a TAPM with a halfwavelength resonator and six different working gases: helium, neon, argon, carbon dioxide, oxygen, and nitrogen. The resonator length (LRES) is 1 m and the charged pressures (pm) are in the range of 0.1–2.0 MPa. The stack is a pile of stainless-steel wire-mesh screen with mesh number of 30 and wire diameter of 0.25 mm. The stack length is 4 cm. It is found that Tcrit is depending on the stack location (xSTK) in the resonator and there is an optimum stack location that gives a minimum critical temperature difference ((Tcrit)min). In addition, the (Tcrit)min is influenced by the charged pressure of the gas. The lowest (Tcrit)min, spread from 55 oC to 78 oC, are found in the range of 0.4–0.7 MPa, except for He and Ne are in 1.5–2.0 MPa range. Compared to all other test gases, carbon dioxide has the lowest (Tcrit)min, i.e. 55 oC which occur at 0.4 MPa. Moreover, we found that the optimum ratios of the hydraulic radius of the stack to the thermal penetration depths of all test gases, which give the lowest ((Tcrit)min), are almost the same, i.e. are around 2.1. Furthermore, this study reveals that the gases with large ratios of specific heats () and low Prandtl numbers () give higher (Tcrit)min than those with small and high . |
| Group of Knowledge | : | Fisika |
| Level | : | Internasional |
| Status | : |
Published
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