In this study we investigate mixing under transcritical conditions by means of direct numerical simulation. Atemporal jet configuration is used together with thermodynamic conditions matching those of experiments oncryogenic injection of nitrogen at supercritical pressures. Two cases, representing supercritical and transcriticalconditions, are simulated using a spectral element based, low-Mach numberflow solver, coupled with detailedreal-fluid equation of state and transport properties. The objective is to shed light on the transcritical mixingprocess and to concurrently investigate, in a-priori fashion, the sub-grid scale modeling of thermodynamic andtransport properties in the context of large eddy simulation. Relevant qualitative and statistical differencesbetween supercritical and transcritical jets are observed, despite the same initial Reynolds number. The use of apresumedβ-pdf for sub-grid scale mixing is investigated and is shown to significantly improve, with respect tothe largely used“no-model”, the evaluation of thermodynamic and transport properties.

Mixing under transcritical conditions: an a-priori study using direct numerical simulation / Lapenna, Pasquale Eduardo; Creta, Francesco. - In: THE JOURNAL OF SUPERCRITICAL FLUIDS. - ISSN 0896-8446. - 128(2017), pp. 263-278. [10.1016/j.supflu.2017.05.005]

Mixing under transcritical conditions: an a-priori study using direct numerical simulation

LAPENNA, PASQUALE EDUARDO
;
CRETA, Francesco
2017

Abstract

In this study we investigate mixing under transcritical conditions by means of direct numerical simulation. Atemporal jet configuration is used together with thermodynamic conditions matching those of experiments oncryogenic injection of nitrogen at supercritical pressures. Two cases, representing supercritical and transcriticalconditions, are simulated using a spectral element based, low-Mach numberflow solver, coupled with detailedreal-fluid equation of state and transport properties. The objective is to shed light on the transcritical mixingprocess and to concurrently investigate, in a-priori fashion, the sub-grid scale modeling of thermodynamic andtransport properties in the context of large eddy simulation. Relevant qualitative and statistical differencesbetween supercritical and transcritical jets are observed, despite the same initial Reynolds number. The use of apresumedβ-pdf for sub-grid scale mixing is investigated and is shown to significantly improve, with respect tothe largely used“no-model”, the evaluation of thermodynamic and transport properties.
File allegati a questo prodotto
File Dimensione Formato  
Lapenna_mixing-under-transcritical_2017.pdf

solo gestori archivio

Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 1.81 MB
Formato Adobe PDF
1.81 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11573/981394
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 48
  • ???jsp.display-item.citation.isi??? 34
social impact