Research on heat transfer enhancing mechanism and cooling performance of herringbone groove on rotor outer sidewall in high-speed contact mechanical seals

doi:10.11949/0438-1157.20250449

Abstract

Abstract:

To address the issue of overheating in the end faces of contact mechanical seals under high-speed conditions, a novel contact mechanical seal structure with herringbone grooves on the outer side of the rotating ring was proposed. A fluid-solid heat transfer numerical model was established based on computational fluid dynamics (CFD) to examine the distributions of the flow field, temperature field, pressure field, and velocity field within the seal ring and the seal cavity. The heat transfer characteristics of fluid flow in the herringbone groove region and the seal cavity were analyzed, revealing the convective heat transfer mechanism and cooling principles. The results demonstrate that the pressure differential flow induced by the herringbone groove structure significantly enhances the mixing effect between the fluid near the heat transfer surface and the fluid in the seal cavity. Additionally, it increases the turbulence intensity near the groove walls. This flow thins the hydrodynamic and thermal boundary layers near the outer wall, raises the local Nusselt number, and improves heat transfer efficiency. As rotational speed increases, the heat transfer performance of the herringbone-grooved mechanical seal also improves. The influence of herringbone groove angle, depth, number of grooves, and end-face distance on heat transfer was analyzed, with the number of grooves and end-face distance having the most significant impact. Compared with traditional mechanical seals, the end-to-end temperature rise of mechanical seals with herringbone grooves on the outer side was significantly reduced. At a speed of 10000 r/min, the temperature rise decreased by 38.8 K, a 22.1% reduction. This significant reduction in seal temperature rise provides a theoretical basis for the optimized design and engineering application of high-performance contact mechanical seals.

Key words: contact mechanical seal, herringbone grooves on outer side surface, heat transfer enhancing mechanism, thermal boundary layer thinning, cooling performance

摘要：

为了解决高速工况下接触式机械密封端面过热的问题，提出了一种动环外侧面设有人字槽的接触式机械密封新结构，基于计算流体动力学（CFD）建立了其流固传热数值模型，考察了密封环与密封腔内流场、温度场、压力场和速度场分布，分析了人字槽区与密封腔流体流动传热特性，揭示了对流换热机理与冷却规律。研究结果表明，人字槽结构引发的压差流显著增加了传热表面附近流体与密封腔流体之间的混合效应，提高了人字槽壁面附近流动的湍流强度，该流动减薄了外壁附近的流动和热边界层，增大了局部Nusselt数，强化了换热效果，转速增大时人字槽机械密封的换热性能也随之增强。分析了人字槽角度、槽深、排数以及端面距对换热效果的影响，其中排数与端面距的影响较大。与传统机械密封相比，外侧面人字槽机械密封的端面温升明显下降，转速为10000 r/min时温升下降38.8 K，温度降幅达22.1%，密封温升显著降低，为高性能接触式机械密封的优化设计与工程应用提供了理论依据。

关键词: 接触式机械密封, 外侧面人字槽, 强化换热机理, 热边界层薄化, 冷却性能

CLC Number:

TH 117.2

Xuezhong MA, Qingxiang XIE. Research on heat transfer enhancing mechanism and cooling performance of herringbone groove on rotor outer sidewall in high-speed contact mechanical seals[J]. CIESC Journal, 2025, 76(10): 5277-5289.

马学忠, 谢庆祥. 高速接触式机械密封动环外侧面人字槽强化换热机理与冷却性能研究[J]. 化工学报, 2025, 76(10): 5277-5289.

Figures/Tables 24

Fig.1 Mechanical seal structure

Fig.2 Geometric structure of herringbone groove

Table 1 Geometric and operational parameters

参数	数值
端面距l₁/mm	0.1~0.5
槽间距l₂/mm	0.5
槽宽l₃/mm	0.5
动环长度l₄/mm	5.52
静环长度l₅/mm	5.25
槽深h₁/mm	0.1~0.5
进口高度h₂/mm	2
动环内径d₁/mm	28.9
动环外径d₂/mm	32.5
静环外径d₃/mm	34
密封腔外径d₄/mm	42
动环旋转速率n/(r/min)	1800~10000
槽排数n₁	1~4
槽角度α/(°)	10~25

Table 2 Physical property parameters

参数名称	C₃H₈O₂(密封介质)	碳石墨(静环)	不锈钢(动环)
k/(W/(m·K))	0.29	18	14
ρ/(kg/m³)	1018.42	1825	7900
c/(J/(kg·K))	3200	419	670
μ/(Pa·s)	0.00705	—	—

Table 3 Related parameters of friction heat

参数	数值
ΔP/MPa	0.8
B/%	75
K/%	50
P_sp/MPa	0.3
f	0.1

Fig.3 Boundary conditions

Fig.4 Computational domain mesh division： (a) assembly mesh; (b) local mesh of herringbone groove wall; (c) local mesh of boundary layer

Fig.5 Grid independence verification

Fig.6 Model validation

Fig.7 (a) Temperature field distribution of rotating and stationary rings, sealing chamber and sealing end face; (b) Temperature variation curve along the radius on the end face

Fig.8 Temperature and pressure distribution at the bottom of the herringbone groove

Fig.9 Thermal boundary layer of the sealing chamber at the x = 0 cross-section

Fig.10 (a) Flow and velocity field in sealing chamber; (b) Pressure distribution in sealing chamber

Fig.11 Streamline and velocity distributions in sealing chamber at different cross-sections

Fig.12 Turbulent kinetic energy at the x = 0 cross-section of the sealing chamber

Fig.13 (a) Nusselt number distribution on outer surface; (b) Wake flow

Fig.14 Effect of herringbone groove angle on temperature

Fig.15 Temperature distribution at different groove angles

Fig.16 Effect of groove depth on temperature

Fig.17 Temperature distributions at different groove depths

Fig.18 Effect of end-face distance on temperature characteristics

Fig.19 Temperature distributions at different end-face distances

Fig.20 Effect of row number on temperature

Fig.21 Temperature distribution at different row numbers

References 34

[1]	郑煜, 朱汉华, 任泓吉, 等. 船舶艉轴机械密封温度场与热变形分析[J]. 润滑与密封, 2021, 46(3): 110-118.
	Zheng Y, Zhu H H, Ren H J, et al. Research on temperature field and thermal deformation of ship's stern shaft mechanical seal[J]. Lubrication Engineering, 2021, 46(3): 110-118.
[2]	Zhang G Y, Chen G Z, Zhao W G, et al. An experimental test on a cryogenic high-speed hydrodynamic non-contact mechanical seal[J]. Tribology Letters, 2017, 65(3): 80.
[3]	Ma X Z, Xiao X X. Investigation on the influencing mechanism and quantitative evaluation of stirred heat effect in high-speed mechanical seals[J]. Case Studies in Thermal Engineering, 2025, 67: 105839.
[4]	Ha D, Roh T S, Huh H, et al. Development trend of liquid hydrogen-fueled rocket engines (part 2): Core technologies[J]. International Journal of Aeronautical and Space Sciences, 2023, 24(1): 146-165.
[5]	Nosaka M. Cryogenic tribology of high-speed bearings and shaft seals in liquid hydrogen[J]. Tribology Online, 2011, 6(2): 133-141.
[6]	Xiao N, Khonsari M M. Improving thermal performance of mechanical seals via surface texturing[J]. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2015, 229(4): 350-361.
[7]	周宇坤, 彭旭东, 赵文静, 等. 机械密封动环外周表面织构换热机理及结构优化[J]. 摩擦学学报, 2020, 40(4): 538-550.
	Zhou Y K, Peng X D, Zhao W J, et al. Heat transfer mechanism and optimization of circumferential texture of mechanical seal[J]. Tribology, 2020, 40(4): 538-550.
[8]	周宇坤. 密封环外周表面织构对机械密封对流换热效应的影响[D]. 杭州: 浙江工业大学, 2020.
	Zhou Y K. Effect of the outer circumferential surface texture of the seal ring on the convective heat transfer effect of mechanical seals[D]. Hangzhou: Zhejiang University of Technology, 2020.
[9]	余旻丰, 彭旭东, 孟祥铠, 等. 接触式机械密封外圆周织构强化换热机理研究[J]. 中国机械工程, 2023, 34(11): 1268-1279.
	Yu M F, Peng X D, Meng X K, et al. Research on heat transfer enhancement mechanism of contact mechanical seals with textured circumference surfaces[J]. China Mechanical Engineering, 2023, 34(11): 1268-1279.
[10]	Yu M F, Peng X D, Meng X K, et al. The influence of cooling medium and cooling channel on heat transfer of textured seal in presence of viscous dissipation[J]. International Journal of Heat and Fluid Flow, 2024, 107: 109363.
[11]	Saha S K, Singh H. Heat transfer analysis of grooved mechanical seal: a numerical study[J]. International Communications in Heat and Mass Transfer, 2024, 156: 107700.
[12]	Ahmed M S, Elsayed K, El-shaer Y, et al. Enhancing heat transfer in various grooved annular for Taylor-Couette-Poiseuille flow[J]. Applied Thermal Engineering, 2024, 250: 123489.
[13]	Xiao N, Khonsari M M. Improving bearings thermal and tribological performance with built-In heat pipe[J]. Tribology Letters, 2015, 57(3): 31.
[14]	Xie F S, Li Y Z, Ma Y, et al. Cooling behaviors of a novel flow channel in mechanical seals of extreme high-speed rotation for cryogenic rockets[J]. Cryogenics, 2020, 107: 103055.
[15]	Khoshvaght-Aliabadi M, Sahamiyan M, Hesampour M, et al. Experimental study on cooling performance of sinusoidal–wavy minichannel heat sink[J]. Applied Thermal Engineering, 2016, 92: 50-61.
[16]	Zhang L Y, Duan R J, Che Y, et al. A numerical analysis of fluid flow and heat transfer in wavy and curved wavy channels[J]. International Journal of Thermal Sciences, 2022, 171: 107248.
[17]	Sui Y, Teo C J, Lee P S. Direct numerical simulation of fluid flow and heat transfer in periodic wavy channels with rectangular cross-sections[J]. International Journal of Heat and Mass Transfer, 2012, 55(1/2/3): 73-88.
[18]	Gong L, Kota K, Tao W Q, et al. Parametric numerical study of flow and heat transfer in microchannels with wavy walls[J]. Journal of Heat Transfer, 2011, 133(5): 051702.
[19]	Lin L, Zhao J, Lu G, et al. Heat transfer enhancement in microchannel heat sink by wavy channel with changing wavelength/amplitude[J]. International Journal of Thermal Sciences, 2017, 118: 423-434.
[20]	Sui Y, Teo C J, Lee P S, et al. Fluid flow and heat transfer in wavy microchannels[J]. International Journal of Heat and Mass Transfer, 2010, 53(13/14): 2760-2772.
[21]	Sui Y, Lee P S, Teo C J. An experimental study of flow friction and heat transfer in wavy microchannels with rectangular cross section[J]. International Journal of Thermal Sciences, 2011, 50(12): 2473-2482.
[22]	Mohammed H A, Gunnasegaran P, Shuaib N H. Numerical simulation of heat transfer enhancement in wavy microchannel heat sink[J]. International Communications in Heat and Mass Transfer, 2011, 38(1): 63-68.
[23]	Mohammed H A, Gunnasegaran P, Shuaib N H. Influence of channel shape on the thermal and hydraulic performance of microchannel heat sink[J]. International Communications in Heat and Mass Transfer, 2011, 38(4): 474-480.
[24]	Zheng Z Y, Fletcher D F, Haynes B S. Laminar heat transfer simulations for periodic zigzag semicircular channels: chaotic advection and geometric effects[J]. International Journal of Heat and Mass Transfer, 2013, 62: 391-401.
[25]	Xie G N, Chen Z Y, Sunden B, et al. Numerical predictions of the flow and thermal performance of water-cooled single-layer and double-layer wavy microchannel heat sinks[J]. Numerical Heat Transfer, Part A: Applications, 2013, 63(3): 201-225.
[26]	Xie G N, Chen Z Y, Sunden B, et al. Comparative study of the flow and thermal performance of liquid-cooling parallel-flow and counter-flow double-layer wavy microchannel heat sinks[J]. Numerical Heat Transfer, Part A: Applications, 2013, 64(1): 30-55.
[27]	Liu F Y, Li Y F, Yu B, et al. Experimental research on sealing performance of liquid film seal with herringbone-grooved composite textures[J]. Tribology International, 2023, 178: 108005.
[28]	Liu F Y, Yu B, Li Y F, et al. Experimental study on lubrication characteristics and leakage inhibition of oil-lubricated seal with herringbone grooves[J]. Tribology International, 2023, 187: 108751.
[29]	Luan W L, Liu Y, Wang Y L, et al. Effect of herringbone groove structure parameters on the static performance of gas foil herringbone groove thrust bearings[J]. Tribology International, 2023, 177: 107979.
[30]	Xu L S, Wu J H, Yuan X Y, et al. Influence of inlet pressure disturbance on transient performance of liquid oxygen lubricated mechanical seal and rub-impact phenomenon caused by excitation overload[J]. Tribology International, 2023, 178: 108058.
[31]	Xu L S, Liu Y Y, Wu J H, et al. Transient dynamic analysis and experimental verification on lubrication regime transition during startup period of non-contacting mechanical seal in liquid oxygen turbopump[J]. Tribology International, 2022, 176: 107932.
[32]	Menter F R. Review of the shear-stress transport turbulence model experience from an industrial perspective[J]. International Journal of Computational Fluid Dynamics, 2009, 23(4): 305-316.
[33]	Luan Z G, Khonsari M M. Analysis of conjugate heat transfer and turbulent flow in mechanical seals[J]. Tribology International, 2009, 42(5): 762-769.
[34]	Merati P, Okita N, Jacobs L. Experimental and computational investigation of flow and thermal behavior of a mechanical seal[J]. Tribology Transactions, 1999, 42(4): 731-738.