Nitrous oxide (N2O), a common oxidizer in hybrid rockets, may be used as an effective cooling agent; the potential uses for aerospike nozzles are particularly appealing. So far, there have been little efforts to characterize nitrous oxide as a two-phase flow cooling agent. In order to study nitrous oxide in this context, a Rayleigh tube apparatus developed at Cal Poly was used. Heat transfer coefficient in the nucleate boiling region is investigated by combining experimental and numerical modeling. This included the application of a homogeneous flow model along with a correlation proposed by Shah. The poor agreement obtained, however, has motivated the authors to introduce a modification to the Shah correlation that considers an “effective” Boiling number, defined as 35% of the actual boiling number, Bo. This modification reduces the overall mean absolute deviation between experiment and model from 68.0% to 13.0%, and provides agreement to within 3% at low flow quality, suggesting a lower influence of bubble nucleation on heat transfer in the case of nitrous oxide compared to other two-phase fluids.
Modeling of Saturated and Superheated N2O Heat Transfer Rates, with Experimental Verification / Arribas, Pablo Sánchez; Patrick, Lemieux; Pastrone, Dario Giuseppe. - (2015). (Intervento presentato al convegno 51st AIAA/SAE/ASEE Joint Propulsion Conference, Propulsion and Energy Forum, tenutosi a Orlando, Florida, USA nel luglio 2015) [10.2514/6.2015-3742].
Modeling of Saturated and Superheated N2O Heat Transfer Rates, with Experimental Verification
PASTRONE, Dario Giuseppe
2015
Abstract
Nitrous oxide (N2O), a common oxidizer in hybrid rockets, may be used as an effective cooling agent; the potential uses for aerospike nozzles are particularly appealing. So far, there have been little efforts to characterize nitrous oxide as a two-phase flow cooling agent. In order to study nitrous oxide in this context, a Rayleigh tube apparatus developed at Cal Poly was used. Heat transfer coefficient in the nucleate boiling region is investigated by combining experimental and numerical modeling. This included the application of a homogeneous flow model along with a correlation proposed by Shah. The poor agreement obtained, however, has motivated the authors to introduce a modification to the Shah correlation that considers an “effective” Boiling number, defined as 35% of the actual boiling number, Bo. This modification reduces the overall mean absolute deviation between experiment and model from 68.0% to 13.0%, and provides agreement to within 3% at low flow quality, suggesting a lower influence of bubble nucleation on heat transfer in the case of nitrous oxide compared to other two-phase fluids.Pubblicazioni consigliate
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https://hdl.handle.net/11583/2629128
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