Macroscopic spray characteristics and internal structure studies of natural gas injection

Pham, Quangkhai1; Chang, Mengzhao2; Kalwar, Ankur3; Agarwal, Avinash Kumar3; Park, Sungwook4; Choi, Byungchul1,5; Park, Suhan6

2023-01-15

10.1016/j.energy.2022.126055

ENERGY   Impact Factor & Quartile

0360-5442

1873-6785

The macroscopic spray characteristics and internal structure of a highly expanded compressed natural gas (Methane; CH4) spray were experimentally and numerically investigated. The spray jet characteristics were analyzed under various pressure ratios (PR), defined as the ratio of the methane injection pressure to the ambient pressure. The spray characteristics and shockwave structures were investigated using Schlieren imaging. The novelty originates from comparing the methane spray development and shockwave parameters under low PR (4 < PR < 9) conditions. The investigation included an evaluation of the effect of choking phenomena on gas flow at different PRs by changing the methane injection pressure. The results showed that a high injection pressure did not improve the spray tip penetration but increased the choking phenomenon in methane flow in the near-field region. This phenomenon is a key factor that strongly influences the shockwave structure and leads to 3.5% longer injection duration and at least 13% increase in the spray volume and area before entering the fully developed region of the Mach disk. With respect to the Mach disk parameters, a PR change from 6 to 9 enhanced the Mack disk height by at least 13.5% and its width by at least 29%. Increasing the Mach disk width with PR increased the methane near-field angle of the spray by at least 29%, triple-point angle by at least 29%, and spray width at the triple point by at least 29% because of the larger radial gas spray development. Overall, the comparison of the macroscopic spray characteristics and Mach disk parameters showed that the macroscopic spray parameters were almost similar despite the changes in the PRs. In contrast, the Mach disk parameters (height, width, and triple point angle) and variations in the methane spray field were larger than those in the macroscopic spray parameters. In addition, the simulation results were used to analyze the energy conservation and transfer conversion efficiencies of the gaseous injection system. The same increase in PR led to greater energy transfer and conversion efficiencies by 0.05% and 6.7%, respectively, which adversely affects charge mixing in the intake manifold. Strong air turbulence is required to enhance the charge-mixing mechanism and achieve a homogeneous fuel-air mixture. Therefore, the choking phenomenon requires more attention when implementing gaseous injection systems for internal combustion engines.

Macroscopic spray Gaseous injection Shock-wave structure Mach disk Nozzle pressure ratio Methane

SCI

English

Others

Basic Science Research Program[2019R1A2C1089494] ; National Research Foundation of Korea (NRF) under the India-Korea INTERNATIONAL COOPERATION Program[2020K1A3A1A19088692]

Thermodynamics ; Energy & Fuels

Thermodynamics ; Energy & Fuels

WOS:000913259200001

PERGAMON-ELSEVIER SCIENCE LTD

ENGINEERING

Web of Science

1.Grad Sch Chonnam Natl Univ, Dept Mech Engn, 77 Yongbong Ro, Gwangju 61186, South Korea
2.Southern Univ Sci & Technol SUSTech, Dept Mech & Aerosp Engn, Shenzhen 518055, Peoples R China
3.Indian Inst Technol Kanpur, Dept Mech Engn, Engine Res Lab, Kanpur 208016, India
4.Hanyang Univ, Sch Mech Engn, Seoul 04763, South Korea
5.Chonnam Natl Univ, Sch Mech Engn, 77 Yongbong Ro, Gwangju 61186, South Korea
6.Konkuk Univ, Sch Mech & Aerosp Engn, 120 Neungdong Ro, Seoul 05029, South Korea

Pham, Quangkhai,Chang, Mengzhao,Kalwar, Ankur,et al. Macroscopic spray characteristics and internal structure studies of natural gas injection[J]. ENERGY,2023,263.

Pham, Quangkhai.,Chang, Mengzhao.,Kalwar, Ankur.,Agarwal, Avinash Kumar.,Park, Sungwook.,...&Park, Suhan.(2023).Macroscopic spray characteristics and internal structure studies of natural gas injection.ENERGY,263.

Pham, Quangkhai,et al."Macroscopic spray characteristics and internal structure studies of natural gas injection".ENERGY 263(2023).