Flutter in a simplified blade cascade: Limits of the quasi-steady approximation

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F23%3A00573425" target="_blank" >RIV/61388998:_____/23:00573425 - isvavai.cz</a>

Alternative codes found

RIV/46747885:24220/23:00011172

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0889974623000816" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0889974623000816</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jfluidstructs.2023.103913" target="_blank" >10.1016/j.jfluidstructs.2023.103913</a>

Result language

angličtina

Original language name

Flutter in a simplified blade cascade: Limits of the quasi-steady approximation

Original language description

Flow-induced vibration in turbomachinery represents a major and persistent concern, especially in modern turbine and compressor designs with long and slender blades operating in transonic flow conditions. There is a wide range of computational and experimental methods for blade flutter prediction and analysis. In certain situations, the quasi-steady approximation can be utilized, considering the unsteady flow as a sequence of steady flow fields for each position of the oscillation cycle. The study is focused on experimental investigation of the limits of applicability of the quasisteady approximation in the case of a simplified linear five-blade cascade with the middle blade undergoing high-frequency torsional oscillation due to kinematic excitation. A measurement campaign of more than 100 wind tunnel runs was carried out for flow velocities ranging from high subsonic to transonic regimes (M = 0, 0.529, 0.777 and 1.018), frequency ratios 0 - 0.75 and reduced frequencies k = 0 – 0.41. A comparison of quasi-steady and time-resolved blade surface pressure measurements is reported, and the degree of unsteadiness of the airflow is quantified. For low reduced frequencies the stationary distributions match almost perfectly the time-resolved profiles. The degree of unsteadiness remains below 2% up to k = 0.1 for the subsonic and supercritical flow regimes. For reduced frequencies above 0.2, the global degree of unsteadiness increases quickly up to 10%, with local differences between the stationary and time-resolved pressure profiles up to 40%. In the case of transonic flow regime, the flow unsteadiness is generally higher and further complicated by intermittency — stochastic transition from supersonic to subsonic flow in the aft part of the blade.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20302 - Applied mechanics

Project

<a href="/en/project/GA20-11537S" target="_blank" >GA20-11537S: Experimental research on flutter excitation function in turbomachinery</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Fluids and Structures

ISSN

0889-9746

e-ISSN

1095-8622

Volume of the periodical

120

Issue of the periodical within the volume

July

Country of publishing house

GB - UNITED KINGDOM

Number of pages

15

Pages from-to

103913

UT code for WoS article

001033077100001

EID of the result in the Scopus database

2-s2.0-85161556469