An improved partially-averaged Navier-Stokes model for secondary flows

Abstract In the present study, the modified formulations of the partially-averaged Navier-Stokes (PANS) model were suggested for accurate prediction of the secondary flow by resolving the anisotropy of turbulence. The main characteristics of the modified PANS (mPANS) models were to resolve the wide range of turbulent length scale by decreasing fk value in the region where the anisotropic behavior of turbulence […]

Automation of load balancing for Gantt planning using reinforcement learning

Abstract Typically, in the shipbuilding industry, several vessels are built concurrently, and a production plan is established through a hierarchical planning process. This process largely comprises strategic planning (long-term) and master planning (mid-term) aspects. The portion that requires the most manual work of the planner is the load balancing in the master planning stage. The load […]

Techno-economic versus energy optimization of natural gas liquefaction processes with different heat exchanger technologies

Abstract The energy intensity of the natural gas liquefaction process in LNG value chains is considerable, and therefore a number of energy optimization studies have been conducted to obtain optimal operating conditions and maximize process efficiency. In order to limit the size and cost of heat exchangers during energy optimization, a minimum temperature approach constraint […]

Design methodology for mass transfer-enhanced large-scale electrochemical reactor for CO2 reduction

Abstract The electrochemical conversion of CO2 using a continuous flow membrane reactor is a promising technology. This is because the membrane reactor can achieve high productivity and selectivity by enhancing the mass transfer of CO2. In an industrial-scale reactor, the extrinsic properties that facilitate the mass transfer rate are crucial because the uniform flow distribution and high production rate can […]

Advanced boil-off gas studies for liquefied natural gas

Abstract Current methods of estimating boil-off gas (BOG) rates for large-scale liquefied natural gas (LNG) storage tanks are largely empirical and based on limited available experimental data. More accurate models would be extremely valuable for estimating the potential for excessive BOG generation during LNG storage and transportation scenarios as well as providing critical inputs into […]

An electrical resistivity-based method for measuring semi-clathrate hydrate formation kinetics: Application for cold storage and transport

Abstract Tetra-n-butylammonium bromide (TBAB) semi-clathrate hydrate has a large latent heat and suitable phase transition temperatures to be used as a phase change material for cold energy storage and transport. The mass fraction of hydrates in the semi-clathrate hydrate slurry is a key parameter determining the cold carrying capacity and flow properties. We developed a […]

Acoustic radiation efficiency of a submerged periodic ring-stiffened cylindrical shell with finite vibration loading

Abstract The acoustic radiation efficiency of a cylindrical shell is an important parameter in estimating the sound radiation emitted by a structure. However, many of the relevant previous studies have approached acoustic radiation problem by employing numerical methods, requiring large computational resources. In this study, an analytical method is developed to calculate the acoustic radiation […]

Advanced boil-off gas studies of liquefied natural gas used for the space and energy industries

Abstract Growing interest in liquefied natural gas (LNG) as a rocket fuel demands reliable prediction and an improved understanding of the changes in its composition arising from the preferential boil-off of lighter components during long duration storage. Unfortunately, current methods of predicting boil-off gas (BOG) evolution from cryogenic liquids are based on limited experimental data. This work […]

Speed excursion simulation of PIG using improved friction models

Abstract This study proposes two novel friction models of pipeline inspection gauges (PIGs) to simulate and predict speed excursions in long pipeline system pigging operations. Speed excursion of PIG indicates its sudden acceleration mainly caused by gas compressibility and frictional variation in low-pressure and low-flowrate gas pipelines. The first friction model adopts a dynamic friction table coupled with an exponential friction model to simulate […]