Discharge coefficient measurements of film-cooling holes with expanded exits

Journal Article · Wed Jul 01 04:00:00 EDT 1998 · Journal of Turbomachinery

DOI:https://doi.org/10.1115/1.2841753· OSTI ID:290032

Gritsch, M; Schulz, A; Wittig, S ^[1]

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

This paper presents the discharge coefficients of three film-cooling hole geometries tested over a wide range of flow conditions. The hole geometries include a cylindrical hole and two holes with a diffuser-shaped exit portion (i.e., a fan-shaped and a laidback fan-shaped hole). The flow conditions considered were the crossflow Mach number at the hole entrance side (up to 0.6), the crossflow Mach number at the hole exit side (up to 1.2), and the pressure ratio across the hole (up to 2). The results show that the discharge coefficient for all geometries tested strongly depends on the flow conditions (crossflows at hole inlet and exit, and pressure ratio). The discharge coefficient of both expanded holes was found to be higher than of the cylindrical hole, particularly at low pressure ratios and with a hole entrance side crossflow applied. The effect of the additional layback on the discharge coefficient is negligible.

• Sponsoring Organization: USDOE
• OSTI ID: 290032
• Report Number(s): CONF-970604--
• Journal Information: Journal of Turbomachinery, Journal Name: Journal of Turbomachinery Journal Issue: 3 Vol. 120; ISSN JOTUEI; ISSN 0889-504X
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
33 ADVANCED PROPULSION SYSTEMS
FILM COOLING
ORIFICES
SHAPE
SIZE
TURBINE BLADES