Convective Heat Transfer Coefficient Model Under Nanofluid Minimum Quantity Lubrication Coupled with Cryogenic Air Grind
- PDF / 4,665,256 Bytes
- 23 Pages / 595.276 x 790.866 pts Page_size
- 7 Downloads / 236 Views
Online ISSN 2198-0810 Print ISSN 2288-6206
REGULAR PAPER
Convective Heat Transfer Coefficient Model Under Nanofluid Minimum Quantity Lubrication Coupled with Cryogenic Air Grinding Ti–6Al–4V Jianchao Zhang1 · Wentao Wu1 · Changhe Li1 · Min Yang1 · Yanbin Zhang1 · Dongzhou Jia2 · Yali Hou1 · Runze Li3 · Huajun Cao4 · Hafiz Muhammad Ali5 Received: 30 July 2019 / Revised: 13 July 2020 / Accepted: 7 September 2020 © Korean Society for Precision Engineering 2020
Abstract Under the threat of serious environmental pollution and resource waste, sustainable development and green manufacturing have gradually become a new development trend. A new environmentally sustainable approach, namely, cryogenic air nanofluid minimum quantity lubrication (CNMQL), is proposed considering the unfavorable lubricating characteristic of cryogenic air (CA) and the deficient cooling performance of minimum quantity lubrication (MQL). However, the heat transfer mechanism of vortex tube cold air fraction by CNMQL remains unclear. The cold air fraction of vortex tubes influences the boiling heat transfer state and cooling heat transfer performance of nanofluids during the grinding process. Thus, a convective heat transfer coefficient model was established based on the theory of boiling heat transfer and conduction, and the numerical simulation of finite difference and temperature field in the grinding zone under different vortex tube cold air fractions was conducted. Simulation results demonstrated that the highest temperature initially declines and then rises with increasing cold air fraction. Afterward, this temperature reaches the lowest peak (192.7 °C) when the cold air fraction is 0.35. Experimental verification was conducted with Ti–6Al–4V to verify the convective heat transfer coefficient model. The results concluded that the low specific grinding energy (66.03 J/mm3), high viscosity (267.8 cP), and large contact angle (54.01°) of nanofluids were obtained when the cold air fraction was 0.35. Meanwhile, the lowest temperature of the grinding zone was obtained (183.9 °C). Furthermore, the experimental results were consistent with the theoretical analysis, thereby verifying the reliability of the simulation model. Keywords Grinding · Nanofluid minimum quantity lubrication · Vortex tube · Cold air fraction · Convective heat transfer coefficient · Temperature field Jianchao Zhang and Wentao Wu have contributed equally to this work. * Changhe Li [email protected]
Runze Li [email protected]
* Hafiz Muhammad Ali [email protected]
Huajun Cao [email protected]
Jianchao Zhang [email protected]
1
Wentao Wu [email protected]
School of Mechanical and Automotive Engineering, Qingdao University of Technology, Qingdao 266520, China
2
Min Yang [email protected]
School of Mechanical Engineering, Inner Mongolia University for Nationalities, Tongliao 028000, China
3
Yanbin Zhang [email protected]
Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089‑1111, USA
4
Dongzh
Data Loading...
