We consider balanced flows in a natural gas transmission network and discuss computationally hard problems such as establishing if solution of the underlying nonlinear gas flow equations exists, if it is unique, and finding the solution. Particular topologies, e.g. trees, are known to be easy to solve based on a variational description of the gas flow equations, but these approaches do not gene...

A model for simulating vertical water level fluctuations with coupled liquid and gas phases is presented. The Preissmann implicit scheme is used to linearize the governing equations for one-dimensional transient flow for both liquid and gas phases, and the linear system is solved using the chasing method. Some classical cases for single liquid and gas phase transients in pipelines and networks ...

Abstract An analysis into the transient natural convective flow of a nanofluid in vertical tube is made. The governing equations momentum, heat transfer and nanoparticle volume fraction are deduced, influence thermophoresis parameter Brownian motion incorporated. By direct integration variation parameter, analytical solutions obtained for formation heat/mass at steady-state. On other hand, due ...

In this paper, we use the Global Gas Model to analyze the perspectives and infrastructure needs of the European natural gas market until 2050. Three pathways of natural gas consumption in a future low-carbon energy system in Europe are envisaged: i) a decreasing natural gas consumption, along the results of the PRIMES model for the EMF decarbonization scenarios; ii) a moderate increase of natur...

In this study, a 1-D transient state mechanistic model of cuttings transport with foam in inclined wells has been developed. The model is solved numerically to predict the optimum foam flow rate (liquid and gas rate) and rheological properties that would maximize cuttings transport efficiency in inclined wells. A detailed sensitivity analysis of the effect of gas and liquid flow rates, drilling...

A numerical model was developed to predict gas-phase nucleation of particles during silane pyrolysis. The model includes a detailed clustering mechanism for the formation of hydrogenated silicon clusters containing up to ten silicon atoms. This mechanism was coupled to an aerosol dynamics moment model to predict particle growth, coagulation, and transport. Both zero-dimensional transient simula...

Direct numerical simulations of unsteady natural convection in a differentially heated cavity with a thin fin of different lengths on a sidewall at the Raleigh number of 3.8 × 10 are performed. It is found that the fin length significantly impacts on the transient thermal flow around the fin and heat transfer through the finned sidewall in the early stage of the transient flow development. The ...

In this letter, we propose a market-based bi-level conic optimal energy flow (OEF) model of integrated electricity and natural gas systems (IENGSs). Conic alternating current power (ACOPF) is formulated in the upper-level model, generation cost fired units (NGFGUs) calculated based on locational marginal prices (NG-LMPs). The market clearing process system modeled lower-level model. bilevel the...