View in EDS

Shock loss measurements in non-ideal supersonic flows of organic vapors.

Saved in:
Bibliographic Details
Title: Shock loss measurements in non-ideal supersonic flows of organic vapors.
Authors: Conti, Camilla C.1 (AUTHOR) camillacecilia.conti@polimi.it, Fusetti, Alberto2 (AUTHOR), Spinelli, Andrea2 (AUTHOR), Guardone, Alberto1 (AUTHOR)
Source: Experiments in Fluids. Jul2022, Vol. 63 Issue 7, p1-11. 11p.
Subjects: Politecnico di Milano, Supersonic flow, Mach number, Vapors, Fluid dynamics, Gases
Abstract: This paper presents the first ever direct measurements of total pressure losses across shocks in supersonic flows of organic vapors in non-ideal conditions, so in the thermodynamic region close to the liquid–vapor saturation curve and the critical point where the ideal gas law is not applicable. Experiments were carried out with fluid siloxane MM (hexamethyldisiloxane, C 6 H 18 OSi 2 ), commonly employed in medium-/high-temperature organic Rankine cycles (ORCs), in the Test Rig for Organic VApors (TROVA), a blowdown wind tunnel at the Laboratory of Compressible fluid dynamics for Renewable Energy Applications (CREA lab) of Politecnico di Milano. A total pressure probe was inserted in superheated MM vapor flow at Mach number ∼ 1.5 with total conditions in the range 215 - 230 ∘ C and 2 - 12 bar at varying levels of non-ideality, with a compressibility factor evaluated at total conditions between Z T = 0.68 - 0.98 . These operating conditions are representative of the first-stage stator of ORC turbines. Measured shock losses were compared with those calculated from pre-shock quantities by solving conservation equations across a normal shock, with differences always below 2 % attesting a satisfactory reliability of the implemented experimental procedure. An in-depth analysis was then carried out, highlighting the direct effects of non-ideality on shock intensity. Even at the mildly non-ideal conditions with Z T ≳ 0.70 considered here, non-ideality was responsible for a significantly stronger shock compared to the ideal gas limit at same pre-shock Mach number, with differences as large as 6 % . [ABSTRACT FROM AUTHOR]
Copyright of Experiments in Fluids is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:This paper presents the first ever direct measurements of total pressure losses across shocks in supersonic flows of organic vapors in non-ideal conditions, so in the thermodynamic region close to the liquid–vapor saturation curve and the critical point where the ideal gas law is not applicable. Experiments were carried out with fluid siloxane MM (hexamethyldisiloxane, C 6 H 18 OSi 2 ), commonly employed in medium-/high-temperature organic Rankine cycles (ORCs), in the Test Rig for Organic VApors (TROVA), a blowdown wind tunnel at the Laboratory of Compressible fluid dynamics for Renewable Energy Applications (CREA lab) of Politecnico di Milano. A total pressure probe was inserted in superheated MM vapor flow at Mach number ∼ 1.5 with total conditions in the range 215 - 230 ∘ C and 2 - 12 bar at varying levels of non-ideality, with a compressibility factor evaluated at total conditions between Z T = 0.68 - 0.98 . These operating conditions are representative of the first-stage stator of ORC turbines. Measured shock losses were compared with those calculated from pre-shock quantities by solving conservation equations across a normal shock, with differences always below 2 % attesting a satisfactory reliability of the implemented experimental procedure. An in-depth analysis was then carried out, highlighting the direct effects of non-ideality on shock intensity. Even at the mildly non-ideal conditions with Z T ≳ 0.70 considered here, non-ideality was responsible for a significantly stronger shock compared to the ideal gas limit at same pre-shock Mach number, with differences as large as 6 % . [ABSTRACT FROM AUTHOR]
ISSN:07234864
DOI:10.1007/s00348-022-03465-y