超高負荷軸流タービン直線翼列内の翼端漏れ流れの挙動

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超高負荷軸流タービン直線翼列内の翼端漏れ流れの挙動

著者辻田星歩, 金子雅直

出版者法政大学情報メディア教育研究センター

雑誌名法政大学情報メディア教育研究センター研究報告

巻 32

ページ 22‑32

発行年 2018‑06‑01

URL http://doi.org/10.15002/00014880

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Œq 2018Ó3Ć16Ā ŅŴ 2018Ó6Ć1Ā

超

超高高負負荷荷軸軸流流タターービビンン直直線線翼翼列列内内のの翼翼端端漏漏れれ流流れれのの挙挙動動 -

-翼翼端端間間隙隙高高ささのの影影響響--

Behavior of Tip Leakage Flow in Ultra-highly Loaded Axial Turbine Linear Cascade

-

Influence of Tip Clearance Size

--

ƔŃ ăĠ^ƻƸơ¾ Ʃŉ^ƼƸ Hoshio Tsujita and Masanao Kaneko

ƻƸĨ÷¼ÁĿÍÁƝěĖÍÁŐ

ƼƸĎoƬě¼ÁĿÍÁƝƬ¾běĖÍÁŚ

In this study, the computations were performed for the flows in an ultra-highly loaded turbine cascade (UHLTC) with high turning angle of 160 degrees in order to clarify the effects of the tip clearance size on the behavior of tip leakage flow and the associated loss generation. The computed results clarified that the loss caused by the tip leakage vortex was higher than those by the horseshoe vortex and the passage vortex. The increase of tip clearance size enhanced the separation of the leakage vortex from the blade suction surface, and consequently decreased the expansion ratio by the decrease of the cascade outlet flow angle.

Keywords : Turbomachinery, Axial turbine, Ultra-highly loading, Tip leakage flow, CFD

1. はじめに

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ŅƬBDKYƳ2.03áƺƹ BDKY kĔ3ð:DGcSa ļ¥f ƹŀ¸ƇŲxĮ *æ10ƺ'ƹ ŰŔł:DGcSa+ƹĹƈ ¥f3¬0 f ƒƠ!ƟŹƁƴ/ƹ.ƹƕÓ GcXU5a9aCa ƶQ8RDĤvƹ

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¡Ŭ0ƺGcSaŨ ƶƇŲ3¬0žŽþĨ

dŨƐ¥Ż ¹0ƹĺnĝĪ1

¹Ú-0õ½¹3×Ɗƺƹç Ŭ3ėïÄł`V_ ƶƇŲGcSaŨ 3ƣŅ0!ƹƶƇŲGcSaŨƝĪ1 i0Üư ƀŜ3Ƃēƹá.1Ōź3µ nĝĪ1¹Ú ïŗ3Ƅ0äŹ0ƺ

ųŪ.!ƶƐ¥Ż3ć0ƋƶƇŲGcSaŉŢ

ŨƷUHLTCƸÆƹƶƇŲvĪƎį,

ƵƏÛį ¹ÚƊª0nĝõ½!šõ½ 40%

ƛƹ.ÇŻ ¹v £!fā 03Ă. 0[1]ƽ[3]ƺGcSaŨ

Ł0nĝĪ1 kƹĪƎįj4nĝõ

½ Łë¼Üư3i0į!ŨŕĴ1į 0ƺ1!©Ɛ0Ũ ŕƭĞ0>c Ba=º ƧƤ3Ɩƚ0ƹŨ®Ư .Ƈ®Ư#

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¥ Ĵ1Ī1lĪÑĭ0-/Ł0ƺ

ĊŎœ! UHLTC ÆƹŨŕƤƧƶŨŕ

Ĵ1į ó-"1Ɗª0õ½Łëi 0Üưƹù~żďŇíĨ(CFD)-/Ƃē ƺ

2. 超高負荷タービン翼列

UHLTC ÛĻlpę3¬1Ŷ111

ŏƺUHLTC !x6DW<MĤƹƶTJI/?cN

ĤƹƐ¥Ż! 160/ƹĢƇŲ|ù!Ɛ¥Ż 110őÕ àč³ ŨĤ$Ŀƃfś 3.5 } ~3ć0ƺ

3. 数値解析法 3.1 計算方法

ĊŎœ!ƹĨ÷¼Áè¶ZL76øūŎœFa Gc ħłCFD?cNSTAR-CD Ver.4.183łƹ ÃÐƮ®ťçĪ13sÃ UHLTC Ī1 ż ď3ŴƺmĪ[L_!ƹºƯ¸ńČtºĨ

3Ɯł0ƶ`8P_Eù³ Ěĳ k-e[L_

3łƺy ŽŘ6_@^EY!SIMPLEĨ 3ƹÆĪƱ ſ{!MARSĨ3łƺċÃ Čt!ƹ öƞþőÖ ġÎ 1.0×10^-5rg ƛ·£ƺ

3.2 解析条件および境界条件

ĊŎœ!ƹŨĪƎƶHÆ0Ũŕ ƤƧƶd Ĥ ņļ(%)Ãŧ10ƤƧƶĤ TCL3R]ZcGƹ13 1.0ƽ3.0' 0.2

(»żď3Ŵ(¬1)ƺ ¸ń

¸ń! 11 ƹŨ f Ī Z/Cax=-1.2 g Ī Z/Cax=2.5žÃƺƹZ/Cax!¬1ŏ- ŨŤ3ĶŨÞŤ3 1.0 0Ƒþ¥ķ ĝƍƫ0ƺ ¸ńČt ¸ńüƯ ƹ TCLÆĪŻa=80 þ¥

ĪƗ 35.0m/s 3iƺŨTJIþ¥ żďƲ

´!1ŨƤƹ TJIþ¥¸ńƯ!§Ĉ

¸ńČt3Ɓƺ ¸ń!ƙş Ö3ıƌ 0ůĸĪČt3ƜłƺŨgĪZ/Cax=1.5 üƯƉƠÒ±ƗÕŨØƢCµReynoldsù!

TCLČtÆś2.6×10⁵0ƺ

ĊżďłŽŘĕ¾3¬2ŏƺH³ Ę Ƙĕ¾-/ÛëƹšF_ù!ś250e0ƺ ŨŕƤƧ DRaþ¥ F_ù!ƹŨŕƤƧ3ô )yºƯ Ŗdĕ¾ĶÆºĨ3Ɯł 0ķĝƍƫy⁺>30 Čt3ıƌ03ũê

ƹTCL=1%Æ!5F_3ƞŦƹ.TCL

0.2%¹0ģ1F_¹,ƹTCL=2%!10 F_ƹ3%!15F_3ƞŦƺ

¬.1 ƋƶƇŲƑĪGcSaŨ

Fig.1 Ultra-highly loaded axial turbine cascade Ŷ1 Ũpę

Table 1 Specification of cascade

Chord length C (mm) 80.0

Axial chord length Cax(mm) 68.5

Aspect ratio H/C 1.25

Pitch-chord ratio S/C 1.43

Maximum thickness-chord ratio tmax/C 1.16 Leading edge metal angle bb₁(degree) 80.0 Trailing edge metal angle bb2(degree) 80.0

¬.2 ŽŘĕ¾ Fig.2 Computational grid

Pressure Surface (PS)

Suction Surface (SS)

Pressure Surface (PS) Suction

Surface (SS) Leading Edge (LE)

Trailing Edge (TE) Blade tip surface

Inlet boundary

Outlet boundary

Periodic boundary Periodic

boundary

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Vol.32 4．結果および考察

4.1 翼端間隙の影響

ŨŕƤƧ ¿¯Ũ Ī1 ó-"õ½ Łëi0Üư3Ƃ$0*ƹŨŕƤƧķ TCL=0.0%ąÈƤƧA8E TCL=1.0% ŝđ3Ĥ ƓũÅ0ƺ

®õ½|ù Cpt üƯƉƠÒ±~Ãŧ10 šõ½|ùCptt ĪƎþ¥Ï3¬3ŏƺCpt! ĝÖÃŧƺ

(1) ƹptref!ŨfĪZ/Cax=-0.50üƯƉƠ Ò±®ƹVout!ŨgĪZ/Cax=1.5 üƯƉƠÒ

±ĪƗ0ƺ¬4!ƹ¬1Ãŧ3ŏŨƑ þ¥Æ0Ī1Ż0\cŻqy üƯƉƠÒ±

~qym ĪƎþ¥Ï3ŏƺ'ƹ¬5üƯƉƠ Ò±ĪƗVm ĪƎþ¥Ï3ŏƺ¬6¬7!ƹ 1 TJI Ƒþ¥²ŉüƯ ƤƧķ TCL=0.0%ƤƧć/ 1.0% ·£ ƹ®õ½Cpt

~űqnĝĪ1ĪŢ311ŏƺ' ƹ¬8¬9TCL=1.0% ·£ ŨŕƯŨƇ

®Ưqƕ Ĵ1Ī1Ĵ1į ĪŢ ę¾3ŏƺ ¬3 .ƹTCL=1.0% þ0.0%Ĥ$ƹšõ

½ Cptt qƕÿƶ0

0ƺ1!¬6(a)7(a) ĤƓ .Ũŕ(Tip)!ƹ

ŤÌƇ®Ư ƵƏÛįVHpƹĴ1Ī 1 Ũ®Ư(PS) . ƤƧ# Ī-/Įŷ 0ƹƤƧ Ĵ1Ī1 õ½ĤƓŇƶ 0*ũ.10ƺŨƤ gĪ¥

TCL=1.0% þƹõ½.ƶ/

Î3¹0ƺ1!¬6(b)(c)7(b)(c) ĤƓ .ƹŨƤgĪ!TipĴ1įVLŅŁ /ƹ kãqƕ õ½ƶ0 .ƹ VL ŅŁƊª0+ 0 0ƺ¬7 8-"9 . VL!ƹŨ®ƯƇ®Ư

Ɲ .ƤƧĪĴ1Ī1ƹƇ®ƯÞƝ .ŨƤĪƎĪ0ƨlĪÑĭ0 -/ŅŁ0 0ƺ'ƹ¬49 . Ĵ1Ī1 ŅŁ!ŨƤÞƝrƦ\

cŻqym3TCL=0.0% ·£-/xgƹĪ1Ż 6aHcGca¥3Ú*0ƺ ŝđƹ¤Ʋ

´qƕ ĪƗVmxg0¬5 .

0ƺŉŢŨ ŨƤ ĪƗ xg!ƹ©Ɛ0

Ũ0ŊÆĪƗÕ xgÆå0*ƹŨ

çŬ3xg0ŮÙļ ĮÉ3ñƺ¬78 -"9 .ƹĴ1įVL!gĪ#¥ Ý

3¹ƹŨgĪTipƶõ½Ʋ´3Ô ř«Ï0 0ƺ¬67 ĤƓ .ƹĴ1įVLƊª0õ½!ƵƏÛįVHp,ĪƎ įVPĤ$ƮÐƶ 0ƺƹ

UHLTC Äł¥ƣŅ!ƹĴ1į

ïîŵ Ɯłh¡Ĝ0ƺ )

2 / /(

) ( _tref _t _out²

pt p p V

C = - r _¬_.3 šõ½|ù ĪƎþ¥Ï Fig.3 Streamwise distribution of total loss

¬.5 üƯƉƠÒ±ĪƗ ĪƎþ¥Ï Fig.5 Streamwise distribution of mass-averaged

velocity over cross section

¬.4 üƯƉƠÒ±\cŻ ĪƎþ¥Ï Fig.4 Streamwise distribution of mass-averaged

yaw angle over cross section

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4.2 翼端間隙高さ(TCL)の影響

¬10¬11ƹ1TJI üƯ TCL=2.0%

3.0% ·£ ®õ½Cpt ~űqnĝ Ī1ĪŢ311ŏƺ¬ 12 !¢Ƒþ¥wŦ Z/Cax0Ĵ1õ½DCpttƤƧƶ TCL ƥ|

3ŏƺƹDCptt!Ĵ1Ī1ŅŁ0¢TCL Cptt .Ĵ1Ī1ŁTCL=0.0% Cptt3Î

×~Ãŧƺ'ƹ¬13TCL=2.0%

3.0% ·£ ŨŕƯqƕ Ĵ1Ī1Ĵ1į ĪŢ3ŏƺ

¬3 .ƹTCL ¹šõ½Cptt¹

0ƺ1!¬710-"11 ĤƓ .ƹTCL ¹-0Ĵ1Ī1 ¹ƹĴ1įVL Ý3¹¹Ú0*0ƺ¬12ŏĴ 1õ½DCptt TCLÆ0¹¥ŋň0ƹ ŨƤ!%&ŢÛŇ¹ƹgĪ#¥ à ƞ¹0 0ƺŨƤ

!ƹ ŢÛçxg TCL=2.0%qƕ3¸

ƞÊìŇ¹0ƺ¬13(a)!ŨƐ¥Ɲqƕ .ŅŁ VL!gĪ#¥ Ƈ®Ư .ß ƫŭƹ ƫŭĶ .gĪ!Ƈ®Ư .ŨƤ Ī0Ĵ1Ī1"Ŗn VL3Ûë0 3ŏ¨0ƺ ĽƆƞ3ÊìŇ¹

ªũ.10ƺŨgĪ!"DCptt

(a) Z/Cax=0.3 (b) Z/Cax=0.8 (c) Z/Cax=0.9 (d) Z/Cax=1.1

¬.6 nĝĪ1ĪŢ®õ½(TCL=0.0%)

Fig.6 Secondary flow streamline colored with total pressure loss on cross-sections (TCL=0.0%)

¬.7 nĝĪ1ĪŢ®õ½(TCL=1.0%)

¬.8 ŨŕƤƧĴ1Ī1Ĵ1į ó(TCL=1.0%) Fig.8 Behaviors of tip leakage flow and leakage

vortex(TCL=1.0%)

¬.9 ŨŕƯƕ Ĵ1Ī1 ó(TCL=1.0%) Fig.9 Behavior of tip leakage flow

near blade tip surface(TCL=1.0%)

PS SS

VHp

VP

VL VL

VP

VL

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¬913 ĤƓ .ƹTCL ¹vĴ1Ī 1 ¹Ú!VL Ƈ®Ư . ƫŭƍƫ3¹ƹ ƫŭĶgĪ ŨƇ®Ư ."Ÿù VL Ł ë3×Ɗũ.10ƺ'ƹ TCL ¹

vƫŭƍƫ ¹v¬4\cŻ qymxgƹĪ1Ż 6aHcGca¥3.

Ú*0ƺ ŝđƹ¬5 .ĪƗVmĮÉƹ ŮÙļxg0 0ƺ

¬.10 nĝĪ1ĪŢ®õ½(TCL=2.0%)

¬.11 nĝĪ1ĪŢ®õ½(TCL=3.0%)

¬.13 ŨŕƯƕ Ĵ1Ī1 ó

Fig.13 Behavior of tip leakage flow near blade tip surface

¬.12 Ĵ1õ½ TCL-0Üư Fig.12 Influence of TCL on tip leakage loss

(a) TCL=2.0%

(b) TCL=3.0%

PS SS

VHp

VL VL

VL

VP

Primary VL

Secondary VL

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5．結論

ƋƶƇŲGcSaŉŢŨ3ÆƆĊŎœ -/rg ŝƃ3áƺ

(1) Ĵ1įƊª0õ½!ƵƏÛį,ĪƎįĤ

$ƶ .ƹĴ1į ïîŵ Ɯłh¡

Ĝ0ƺ

(2) ŨŕƤƧƶ ¹vĴ1į ŨƇ®Ư . ƫŭƍƫ ¹!ƹŨ Ī1Ż 6a HcGca¥3Ú*ƹ ŝđƹŮÙļ3xg 0ƺ

(3) ŨŕƤƧƶ ¹vĴ1Ī1 ¹Ú!ƹ Ĵ1į Ƈ®Ư . ƫŭƍƫ3¹ƹ ƫ ŭĶgĪ ŨƇ®Ư ."Ÿù Ĵ1į Łë3

×Ɗũ.10ƺ

参考文献

[1] ƔŃăĠ, ĥĉýÒƹËĊÀğ, “ƋƶƇŲGcS aŨ Ī1 ù~żď”, ĀĊěĖÁuƃú ƪBţ, Vol.70, No.697 (2004), pp.2332- 2340.

[2] Tsujita, H., Mizuki, S. and Yamamoto, A.,

“Numerical Investigation of Effects of Incidence Angle on Aerodynamic Performance of Ultra-Highly Loaded Turbine Cascade,” Proceedings of ASME Turbo Expo 2006, GT2006-90939 (2006).

[3] Tsujita, H., “Influence of Blade Profile on Secondary Flow in Ultra-Highly Loaded Turbine Cascades at Off-Design Incidence,” Proceedings of ASME Turbo Expo 2013, GT2013-95150, (2013).

超高負荷軸流タービン直線翼列内の翼端漏れ流れの 挙動