Investigations of flow and heat transfer characteristics in wedge-shaped channels embedded with lattice structures

Abstract

Truss-type lattice structures exhibit great application potential for turbine blade cooling. However, current research on lattice structures is limited to rectangular cooling channels, leaving their heat transfer characteristics in the wedge-shaped channels of turbine blades unclear. This study employed transient liquid crystals (TLC) technique and numerical simulations to investigate the flow and heat transfer characteristics of Kagome and Body Centered Cubic (BCC) lattice structures within a wedge-shaped channel, representing the trailing edge of a turbine blade. Results from a traditional pin-fin channel were used as a comparison benchmark. The findings indicate that the decrease in the height of the wedge-shaped channels along the flow direction leads to mainstream acceleration, resulting in a continuous enhancement of heat transfer on the channel walls. Unlike rectangular channels, the pressure loss caused by the lattice structures in the wedge-shaped channels is comparable to that of the pin fins, thereby improving the overall thermal efficiency. Additionally, the unique topology of the Kagome lattice structure causes low-momentum vortex pairs behind its central intersection to continuously rise in the wedge-shaped channel, ultimately washing over the top endwall and resulting in a linear increase in the heat transfer level. Overall, this study reveals that replacing pin fins with lattice structures at the turbine trailing edge can enhance the cooling performance without significantly impacting the pumping power.

Keywords

Lattice structures wedge-shaped channels turbine blades heat transfer enhancement transient liquid crystals

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References

Luo

Jiao

, et al. Heat transfer in the trailing region of gas turbines–A state-of-the-art review. Appl Therm Eng 2021; 199: 117614.

Gupta

Chaube

Verma

. Review on heat transfer augmentation techniques: application in gas turbine blade internal cooling. J Eng Sci. Technol. Rev 2012; 5(1): 57–62.

Liang

Rao

Luo

, et al. Experimental and numerical study of turbulent flow and heat transfer in a wedge-shaped channel with guiding pin fins for turbine blade trailing edge cooling. Int J Heat Mass Tran 2021; 178: 121590.

Chyu

Yen

Siw

. Comparison of heat transfer from staggered pin fin arrays with circular, cubic and diamond shaped elements. In: Turbo Expo: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2007, 47934, pp. 991–999.

Yao

, et al. Heat transfer and pressure loss characteristics of pin-fins with different shapes in a wide channel. In: Heat transfer and pressure loss characteristics of pin-fins with different shapes in a wide channel. American Society of Mechanical Engineers, 2017, vol 50879, p. V05AT16A006.

Ostanek

Thole

. Effects of varying streamwise and spanwise spacing in pin-fin arrays. In: Effects of varying streamwise and spanwise spacing in pin-fin arrays. American Society of Mechanical Engineers, 2012, vol 44700, pp. 45–57.

Chyu

Oluyede

Moon

. Heat transfer on convective surfaces with pin-fins mounted in inclined angles. In: Turbo expo: power for land, sea, and air. American Society of Mechanical Engineers, 2007, vol 47934, pp. 861–869.

Khan

Riccio

. A systematic review of design for additive manufacturing of aerospace lattice structures: current trends and future directions. Prog Aero Sci 2024; 149: 101021.

Kaur

Singh

. Critical evaluation of additively manufactured metal lattices for viability in advanced heat exchangers. Int J Heat Mass Tran 2021; 168: 120858.

10.

Krishnan

Bodla

Weibel

, et al. Numerical investigation of fluid flow and heat transfer in periodic porous lattice-flame materials. In: International heat transfer conference digital library. Begel House Inc., 2014.

11.

Liang

Chen

, et al. Comparing endwall heat transfer among staggered pin fin, Kagome and body centered cubic arrays. Appl Therm Eng 2021; 185: 116306.

12.

Liang

Chen

, et al. Fluid flow and heat transfer performance for micro-lattice structures fabricated by selective laser melting. Int J Therm Sci 2022; 172: 107312.

13.

Parbat

Min

Yang

, et al. Experimental and numerical analysis of additively manufactured inconel 718 coupons with lattice structure. J Turbomach 2020; 142(6): 061004.

14.

Wang

Wei

Wang

, et al. Effective thermal conductivity and heat transfer characteristics for a series of lightweight lattice core sandwich panels. Appl Therm Eng 2020; 173: 115205.

15.

Gao

, et al. Study on flow and heat transfer performance of X-type truss array cooling channel. Case Stud Therm Eng 2021; 26: 101034.

16.

Hwang

Lui

. Measurement of endwall heat transfer and pressure drop in a pin-fin wedge duct. Int J Heat Mass Tran 2002; 45(4): 877–889.

17.

Kan

Yang

Ren

, et al. Effect of rib configuration and lateral ejection on a high aspect ratio trailing edge channel. In: Turbo expo: power for land, sea, and air. American Society of Mechanical Engineers, 2013, vol 55140, p. V03AT12A018.

18.

Facchini

Innocenti

Tarchi

. Pedestal and endwall contribution in heat transfer in thin wedge shaped trailing edge. In: Turbo expo: power for land, sea, and air. American Society of Mechanical Engineers, 2004, 41685, pp. 101–111.

19.

Shen

Yan

, et al. Heat transfer enhancement of wedge-shaped channels by replacing pin fins with Kagome lattice structures. Int J Heat Mass Tran 2019; 141: 88–101.

20.

Patpatiya

Chaudhary

Shastri

, et al. A review on polyjet 3D printing of polymers and multi-material structures. Proc IME C J Mech Eng Sci 2022; 236(14): 7899–7926.

21.

Kan

Guo

Ren

, et al. Determining mainstream reference temperature using the non-dimensional temperature analysis in the transient liquid crystal technique. Int J Heat Mass Tran 2014; 72: 201–209.

22.

Axtmann

von Wolfersdorf

Meyer

. Application of the transient heat transfer measurement technique in a low aspect ratio pin fin cooling channel. J Turbomach 2015; 137(12): 121006.

23.

Axtmann

Poser

von Wolfersdorf

, et al. Endwall heat transfer and pressure loss measurements in staggered arrays of adiabatic pin fins. Appl Therm Eng 2016; 103: 1048–1056.

24.

Chen

Brakmann

Weigand

, et al. An experimental heat transfer investigation of an impingement jet array with turbulators on both target plate and impingement plate. Appl Therm Eng 2020; 166: 114661.

25.

Zhang

Liu

Zhang

, et al. Experimental study of heat transfer and film cooling performance of upstream ejected coolant on a turbine endwall. J Therm Sci 2023; 32(2): 718–728.

26.

Kline

. Describing uncertainties in single-sample experiments. Mech Eng 1963; 75: 3–8.

27.

Yan

Owen

. Uncertainties in transient heat transfer measurements with liquid crystal. Int J Heat Fluid Flow 2002; 23(1): 29–35.

28.

Shen

Yan

, et al. Heat transfer enhancement of wedge-shaped channels by replacing pin fins with Kagome lattice structures. Int J Heat Mass Tran 2019; 141: 88–101.

29.

Yan

Zhang

, et al. A lightweight X-type metallic lattice in single-phase forced convection. Int J Heat Mass Tran 2015; 83: 273–283.

30.

Kaur

Singh

. Endwall heat transfer characteristics of octahedron family lattice-frame materials. Int Commun Heat Mass Tran 2021; 127: 105522.

31.

Liu

Gao

, et al. Numerical study on heat transfer performance of a new-proposed pin-fin in an internal channel[C]//Turbo Expo: Power for Land, Sea, and Air. American Society of Mechanical Engineers. 2017; 50879: V05AT11A014.