Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signatures

Colchester, June 7 2006

Alessandro CORSINI, Bruno Perugini

TMRGroup @ DMA-URLS

Università di Roma "La Sapienza"

D: 7 m³/s AC/90/6/TF AC/90/6

Helicity magnitude is reduced for AC/90/6/TF.Unlike AC/90/6/TF shows helicity sign inversion due to tip vortex breakdown.

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

Tip device reduces vortex rotational energy

evidences from Corsini et al., 2006 (GT2006-90592)

D: 7 m³/sAC/90/6/TF AC/90/6

Stagnation point followed by bubble-type recirculating flow.

Bubble-type breakdown with high loss core

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

evidences from Corsini et al., 2006 (GT2006-90592)

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

Remark 1: vortex breakdown in AC90/6/TF is not correlated to leakage mass flow rate

Remark 2: a correlation exists between the TLV dimension&energy contents (vortex image) and the amount of leakage flows required for the feeding

Remark 2.1: the TLV status is defined by the global flow coefficient (i.e. higher flow rate = higher energy to sustain the vortex development)Remark 2.2: TLV depends on the gap height, on the local incidence angle @ the tip

vL

wn

sc

nc

Lu vRor r

D operating point

P operating point

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

The re-design of end-plate moves from the requirement of avoiding theoccurence of vortex breakdown

Three approaches have been followed:

• modification of tip feature thickness distribution according to safe Rossby number gradient concept – TFvte (TF variable thickness end-plate);

• modification of tip jet energy content at the leading edge geometry – TFcle (TF with circular leading edge);

• modification of tip gap by virtue of a mixing enhancer concept – TFrtg (TF with recessed tip gap).

datum tip geometry, FW July 2005

tip feature thickness modification

circular leading edge datum geometry with stepped or recessed tip

feature

Tip configurations

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

TMRGroup @ DMA-URLS

Colchester, June 2006

TFvte TFcle TFrtg

Helicity

AC/90/6/TF AC/90/6/TFvte

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

Rossby number gradient concept, fan AC/90/6/TFvte

Turbulence Intensity

AC/90/6/TF AC/90/6/TFvte

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

Rossby number gradient concept, fan AC/90/6/TFvte

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

Rossby number gradient concept, fan AC/90/6/TFvte

Rotor losses

AC/90/6/TF AC/90/6/TFvte

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

Leading edge tip jet control, fan AC/90/6/TFcle

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

fan AC/90/6/TFcle vs AC/90/6/TFvte

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

Mixing enhancer concept, fan AC/90/6/TFrtg

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

fan AC/90/6/TFrtg vs AC/90/6/TFvte (i)

losses

TMRGroup @ DMA-URLS

Development of new tip end-plate geometries for improved aerodynamics and aeroacoustics signature

Colchester, June 2006

fan AC/90/6/TFrtg vs AC/90/6/TFvte (ii)

normalized helicity distributions