Huan Zheng^a,*, Yuliang Ma^b , Huaping Mei^c , Xiaohong Xu^a , Xiguang Chen^d , Xunchen Cao^e

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-6, 2018, DOI:10.5098/hmt.11.34

Abstract The supersonic separator has proved to be an effective method to condense and separate CO₂ from natural gas, and the inlet temperature plays a vital role on condensation characteristics of CO₂ in the supersonic separator due to the instability temperature of wellhead natural gas. In this paper, the physical and mathematical models for the supersonic condensation process of CO₂ in the natural gas were established on the basis of CO₂ droplet surface tension, nucleation and growth model. The flow and condensation parameters were investigated under different temperature conditions. The results show that when the inlet gas pressure is 8.0 MPa,… More >

Nidhal Hnaien^a , Salwa Marzouk^a , Lioua Kolsi^a,b,*, Abdullah A.A.A. Al-Rashed^c , Habib Ben Aissia^a , Jacques Jay^d

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-11, 2018, DOI:10.5098/hmt.11.8

Abstract The purpose of the present paper is to numerically investigate two plane turbulent parallel jets using CFD model. A parametric study was carried out to evaluate the simultaneous effect of the nozzle spacing and the velocity ratio on the merge point (MP), the combined points (CP) as well as the upper (UVC) and lower (LVC) vortices centers positions. Results show that the velocity ratio significantly affects twin-parallel jets flow structure. In fact, increasing the velocity ratio moves the MP, CP, UVC and LVC further upstream along the longitudinal direction while deflecting toward the stronger jet along the transverse direction. Due… More >

Tiantian Liu¹, Huimin Pang¹, Suoying He^1,*, Bin Zhao², Zhiyu Zhang¹, Jucheng Wang³, Zhilan Liu⁴, Xiang Huang⁵, Yuetao Shi¹, Ming Gao¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2229-2266, 2023, DOI:10.32604/fdmp.2023.027239

Abstract A review is conducted about the application of the evaporative cooling technology in thermal power plants. Different case studies are considered, namely, evaporative air conditioners, evaporative cooling in direct air-cooled systems, gas turbine inlet cooling, wet cooling towers, and hybrid cooling towers with a crosswind effect. Some effort is provided to describe the advantages related to direct evaporative cooling when it is applied in thermal power plants and illustrate the research gaps, which have not been filled yet. In particular, typical case studies are intentionally used to compare the cooling performances when direct evaporative cooling is implemented in different types… More > Graphic Abstract

Jianfeng Pan^*, Jinpeng Hua, Jiaqi Yao, Abiodun Oluwaleke Ojo

Energy Engineering, Vol.120, No.7, pp. 1541-1562, 2023, DOI:10.32604/ee.2023.027873

Abstract The group-hole nozzle concept is proposed to meet the requirement of nozzle hole minimization and reduce the negative impact of poor spatial spray distributions. However, there are limited researches on the effects of intake conditions and nozzle geometry on spray characteristics of the group-hole nozzle. Therefore, in this study, an accurate spray model coupled with the internal cavitating flow was established and computational fluid dynamics (CFD) simulations were done to study the effects of intake conditions and nozzle geometry on spray characteristics of the group-hole nozzle. Experimental data obtained using high-speed digital camera on the high-pressure common rail injection system… More >

Kapil Dev Choudhary, Shyam Sunder Yadav^† , Mani Sankar Dasgupta

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-10, 2021, DOI:10.5098/hmt.16.14

Abstract In the current work, we simulate the condensation of supercritical CO₂ during its high speed flow inside two different converging-diverging nozzles. We use the homogeneous equilibrium method and the classical nucleation theory based non-equilibrium phase change model for this purpose. The simulation results indicate significant influence of the nozzle inlet condition, nozzle shape and the fluid thermophysical behaviour on the nonequilibrium conditions prevailing inside the nozzles. We observe very low, ∼0.15 K, supercooling for the flow of CO₂ inside the Claudio Lettieri nozzle compared to the supercooling of ∼3 K observed for the Berana nozzle. Very high nucleation rate (∼… More >

V. W. Bhatkar^a,*, Anirban Sur^b,*

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-5, 2021, DOI:10.5098/hmt.17.12

Abstract A jet pump or an ejector uses primary fluid flow as motive fluid to entrained secondary fluid. In this paper, the main intention is to find suction flow rate, primary flow rate, secondary flow rate, loss factors and ejector efficiency for an applied pressure. The values of the different loss factors estimated are primary nozzle loss factor (Kp)=0.06, suction loss factor (Ks)=0.04-0.1, mixing loss factor (Km)=0.07-0.1 and diffuser loss factor (Kd)=0.0289. It is found that with the increase in pressure across the ejector, efficiency increases with increase in flow ratio and decrease in pressure ratio. More >

Yu-Liang Zhang^a , Liang-Huai Tong^b, Jun-Jian Xiao^a,† , Kai-Yuan Zhang^c

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.38

Abstract Nozzle flowmeter has simple structure and wide application. In order to study the influence of temperature change on the inner wall of nozzle flowmeter on the thermal effect of flowmeter, the thermal effect of nozzle flowmeter was numerically simulated at five different inner wall temperatures in this paper. It is found that with the increase of the inner wall temperature, obvious stress concentration occurs in the upstream and downstream pressure inlets and the inlet and outlet areas of the flowmeter, and the thermal stress increases with the increase of the wall temperature. There are large thermal deformation areas in the… More >

Ali Chitsazan^a,*, Georg Klepp^a, Birgit Glasmacher^b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.35

Abstract The objective of the present research is the prediction of large arrays of impingement jets using a computational model. The heat transfer and the force coefficient from single and multiple jet rows (1, 2, 4, 8, and infinity rows) for two different nozzle shapes as either orifice or straight pipe on a fixed flat surface were numerically investigated for drying applications to understand the physical mechanisms which affect the uniformity of the local heat transfer and pressure force coefficient as well as average heat transfer coefficient. The pipe has always a higher averaged Nu and pressure force coefficient compared to… More >

L.H. Tong^a , Y.L. Zhang^b,†, T.H. Yu^a, B.Y. Luo^c, J.F. Li^b

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-8, 2023, DOI:10.5098/hmt.20.10

Abstract In order to explore the thermal characteristics of a small nozzle flowmeter in the solid domain when transporting medium with different temperatures, the steady and transient thermal characteristics of each component of the nozzle flowmeter are calculated based on the finite element method. Results showed that the numerical calculation method could effectively reveal the internal thermal characteristics. When transporting high temperature medium, there was an obvious temperature stratification near the inner wall; when the inner wall temperature rose from 50 °C to 700 °C, the heat flow field at the inlet and outlet of the flowmeter increased significantly with the… More >

Zhong Chen^1,2,*, Yalin Wang^1,2, Yue Li²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1349-1367, 2023, DOI:10.32604/fdmp.2023.024513

Abstract In order to improve the efficiency as well the adaptability and operability of traditional devices used to dredge drainage pipelines a new design is presented here, obtained by matching the structural specifications of a drainage pipeline with the working principle of a high-pressure water jet (HPWJ). To effectively improve the water jet nozzle performances, the nozzle’s structural parameters of the proposed device have been analyzed through Computational fluid dynamics (CFD) simulation. The corresponding behavior of the fluids inside and outside the self-rotational nozzle has been numerically simulated. The final design for the nozzle has been optimized taking into account such… More > Graphic Abstract