Flow field and performance characteristics of combustor diffusers: A basic study

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Journal of Engineering for Gas Turbines and Power

DOI:https://doi.org/10.1115/1.2815454· OSTI ID:169986

Hestermann, R; Kim, S; Ben Khaled, A; Wittig, S ^[1]

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1. Univ. Karlsruhe (Germany). Lehrstuhl und Inst. fuer Thermische Stroemungsmaschinen

Results of a detailed study concerning the influence of geometric as well as fluid mechanic parameters o the performance of a plane model combustor diffuser in cold flow are presented. For a qualitative insight into the complex flow field inside the prediffuser, the sudden expansion region, and the flow field around the flame tube dome, results of a flow visualization study with the hydrogen bubble method as well as with the ink jet method are presented for different opening angles of the prediffuser and for different flame tube distances. Also, quantitative data from detailed measurements with LDV and conventional pressure probes in a geometrically similar air-driven setup are presented. These data clearly demonstrate the effect of boundary layer thickness as well as the influence of different turbulence levels at the entry of the prediffuser on the performance characteristics of combustor diffusers. The possibility of getting an unseparated flow field inside the prediffuser even at large opening angles by appropriately matching the diffuser`s opening angle and the flame tube distance is demonstrated. Also, for flows with an increased turbulence level at the entrance--all other conditions held constant--an increased opening angle can be realized without experiencing flow separation. The comparison of the experimental data with predictions utilizing a finite-volume-code based on a body-fitted coordinate system for diffusers with an included total opening angle less than 18 deg demonstrates the capability of describing the flow field in combustor diffusers with reasonable accuracy.

• Sponsoring Organization: USDOE
• OSTI ID: 169986
• Report Number(s): CONF-940626--
• Journal Information: Journal of Engineering for Gas Turbines and Power, Journal Name: Journal of Engineering for Gas Turbines and Power Journal Issue: 4 Vol. 117; ISSN JETPEZ; ISSN 0742-4795
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
33 ADVANCED PROPULSION SYSTEMS
AUGMENTATION
COMBUSTORS
DIFFUSERS
ENERGY EFFICIENCY
GAS BURNERS
GAS COMPRESSORS
GAS TURBINE ENGINES