Eur. Phys. J. Plus (2017) 132: 234
https://doi.org/10.1140/epjp/i2017-11435-7

Regular Article

Reduced-order modellin for high-pressure transient flow of hydrogen-natural gas mixture

¹ Department of Mathematics, Statistics and Computer Science, Kaduna Polytechnic, Kaduna, Nigeria
² Basic Engineering Science Department College of Engineering, Majmaah University, P.O. Box 66, 11952, Majmaah, Saudi Arabia
³ Department of Mathematics, Faculty of Science, King Abdul Aziz University, Jeddah, Saudi Arabia
⁴ Department of Applied Mathematics, Princess Nourah bint Abdulrahman University Riyadh, Riyadh, Saudi Arabia

^* e-mail: i.said@mu.edu.sa

Received: 20 January 2017
Accepted: 6 March 2017
Published online: 25 May 2017

Abstract

In this paper the transient flow of hydrogen compressed-natural gas (HCNG) mixture which is also referred to as hydrogen-natural gas mixture in a pipeline is numerically computed using the reduced-order modelling technique. The study on transient conditions is important because the pipeline flows are normally in the unsteady state due to the sudden opening and closure of control valves, but most of the existing studies only analyse the flow in the steady-state conditions. The mathematical model consists in a set of non-linear conservation forms of partial differential equations. The objective of this paper is to improve the accuracy in the prediction of the HCNG transient flow parameters using the Reduced-Order Modelling (ROM). The ROM technique has been successfully used in single-gas and aerodynamic flow problems, the gas mixture has not been done using the ROM. The study is based on the velocity change created by the operation of the valves upstream and downstream the pipeline. Results on the flow characteristics, namely the pressure, density, celerity and mass flux are based on variations of the mixing ratio and valve reaction and actuation time; the ROM computational time cost advantage are also presented.