Aerodynamic optimization of ram air turbine rotor of a commercial aircraft /
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Universidad Autónoma de Baja California.
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Ram Air Turbines (RATs) are employed to supply power for auxiliary and backup systems
of an aircraft in case of a major power shortage. These turbines are commonly Horizontal
Axis Wind Turbines (HAWTs). In this study, we investigate the performance of a RAT under
cruise altitude operating conditions. CFD-RANS computations coupled with Blade Element
Method (BEM) are conducted to examine the impact of adding Gurney flaps (GF) to the rotor
blades in terms of power and drag (thrust) performance. Three different GF height
configurations of 1% chord (1%c), 3%c, and 5%c are applied to the blades of a small RAT.
The rotor diameter is 1.016 meters, comprising of two blades with a constant chord length of
0.127 meters and a NACA 8318 airfoil, featuring twist angle along the blade span. The effects
of the Gurney flaps are explored over a Reynolds number range of 200k to 500k based on
the chord length, corresponding to the Reynolds number of the relative wind speed around
the blade at sections of 25%, 50%, 75% and 100% of the blade. Lift coefficient (CL) and drag
coefficient (CD) results were imported to Qblade to perform a BEM turbine analysis. The
results demonstrate a noticeable increase in the maximum coefficient of power around tip
speed ratio (TSR) of 3. Also, a comparison was made between a clean blade and a blade with
GF mounted only at the root of the blade. The blade with GF representing 1% of the chord,
mounted at the root of the blade yields improved CP/CT for a wider range of 3< TSR <6.6.
However, a GF with height of 5%c exhibits the highest CP/CT ratio, both at low TSR (ranging
from 1 to 1.8) and high TSR (from 4 to 7.6). Data validation was conducted for the NACA
8318 airfoil using experimental results from Yoshida (2000). Additionally, data validation
was also performed by comparing the findings with CFD data from Shen (2016) for E387
airfoil performed on the low-speed wind tunnel of Queen Mary University of London. These
validations aim to support and validate the results obtained within this thesis.
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Aerodinámica||Tesis y disertaciones académicas.||lemb||Aviones||Tesis y disertaciones académicas.||lemb||Aerodinámica Matemáticas||Tesis y disertaciones académicas||lemb