Nonlinear Modeling and Analysis of Pressure Wave inside CEUP Fuel Pipeline

Abstract

Operating conditions dependent large pressure variations are one of the working characteristics of combination electronic unit pump (CEUP) fuel injection system for diesel engines. We propose a precise and accurate nonlinear numerical model of pressure inside HP fuel pipeline of CEUP using wave equation (WE) including both viscous and frequency dependent frictions. We have proved that developed hyperbolic approximation gives more realistic description of pressure wave as compared to classical viscous damped wave equation. Frictional effects of various frequencies on pressure wave have been averaged out across valid frequencies to represent the combined effect of all frequencies on pressure wave. Dynamic variations of key fuel properties including density, acoustic wave speed, and bulk modulus with varying pressures have also been incorporated. Based on developed model we present analysis on effect of fuel pipeline length on pressure wave propagation and variation of key fuel properties with both conventional diesel and alternate fuel rapeseed methyl ester (RME) for CEUP pipeline.

Analysis Of Diesel And Rapeseed Methyl Ester Properties In Ceup Fuel Pipeline Using Frequency Dependent Damping Model

“…Improved and more accurate simulated results at 11 different and equidistant points along the fuel pipeline at all combinations of operating conditions mentioned in table 1 have been summarized before [6] but presented here in detail. Simulated results only in the middle of fuel pipeline are discussed at different cam rotational speeds in the following.…”

“…EXPERIMENTAL SETUP Experimental setup of CEUP fuel injection system is shown in figure 1 [1][2][3][4][5][6]. Pressures at pump and injector sides have been recorded at locations indicated in figure 1 where P, c, η and ρ are pressure, acoustic wave speed, absolute or dynamic viscosity and density respectively.…”

“…A simplest approach is by allocating logarithmic weighing to all valid frequency range for CEUP system. A more simplified and selective approach is to consider more frequencies in lower-mid range as compared to midhigh range as reported earlier [6]. Figure 2 …”

“…CEUP is an efficient high pressure [1][2][3][4][5][6] fuel injection system used for heavy duty and marine diesel engines. It consists of combination of high pressure pumps, solenoid control units, fuel pipe lines and mechanical injectors.…”

“…In this paper density, acoustic wave speed and bulk modulus for diesel and RME fuels have been investigated thoroughly using 1D frequency dependent viscous damped pressure wave model [9][10][11][12] developed in MATLAB which has also been reported earlier [6]. Lab experiments have been carried out on CEUP fuel injection system at various operating conditions of diesel engine with both diesel and RME fuels.…”