Ralph Kristoffer B Gallegos

Dr. Ralph Kristoffer B Gallegos

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 September 2017 in Renewable and Sustainable Energy Reviews
Verified
Journal Article
Closed access
Ralph Kristoffer B GallegosRalph Kristoffer B Gallegos
Ralph Kristoffer B Gallegos
RSRajnish Sharma
Rajnish Sharma

1 March 2019 in International Journal of Thermal Sciences
Verified
Journal Article
Closed access
Ralph Kristoffer B GallegosRalph Kristoffer B Gallegos
Ralph Kristoffer B Gallegos
RSRajnish Sharma
Rajnish Sharma

1 February 2024 in Physics of Fluids
Verified
Journal Article
Open access
PDF file
TJTANUJ JOSHI
TANUJ JOSHI
OPOM PARKASH
OM PARKASH
Ralph Kristoffer B GallegosRalph Kristoffer B Gallegos
Ralph Kristoffer B Gallegos
Gopal KrishanGopal Krishan
Gopal Krishan
In this study, a sophisticated three-dimensional computational model was developed to investigate the kinetic and thermal characteristics of a bi-model slurry. This model utilized the Eulerian–Eulerian Re-Normalization Group k–ε turbulence approach in conjunction with the kinetic theory of granular flow. The slurry, composed of different combinations of silica sand and fly ash, was transported through a straight pipeline under varying Prandtl numbers. Five different mixture combinations were considered, ranging from 65% silica sand and 35% fly ash to 100% silica sand. The slurry was transported using four different Prandtl fluids with varying temperatures. The pipe wall was maintained at a constant temperature of 400 K. The computational results yielded significant findings. A mixture with a higher proportion of fly ash (65:35) exhibited superior flow characteristics when combined with a low-viscosity Prandtl fluid (Pr = 2.88), resulting in a minimal pressure gradient and specific energy consumption. Enhanced energy efficiency was observed at lower Reynolds numbers and reduced efflux concentrations. Additionally, the 95:05 mixture demonstrated the highest heat transfer coefficient, with further improvements as flow Reynolds numbers and efflux concentrations increased. These results provide valuable insight into optimizing the transportation of bi-model slurries for various industrial applications, emphasizing the importance of composition and Prandtl numbers.

1 May 2019 in International Journal of Mechanical Sciences
Verified
Journal Article
Closed access
Ralph Kristoffer B GallegosRalph Kristoffer B Gallegos
Ralph Kristoffer B Gallegos
RSRajnish Sharma
Rajnish Sharma

6 December 2024 in Ocean Engineering
Verified
Journal Article
Open access
TJTanuj Joshi
Tanuj Joshi
OPOm Parkash
Om Parkash
Ralph Kristoffer B GallegosRalph Kristoffer B Gallegos
Ralph Kristoffer B Gallegos
GKGopal Krishan
Gopal Krishan

15 September 2024 in Mathematics
Verified
Journal Article
Open access
PDF file
TJTANUJ JOSHI
TANUJ JOSHI
AGAbhinav Gupta
Abhinav Gupta
OPOM PARKASH
OM PARKASH
Ralph Kristoffer B GallegosRalph Kristoffer B Gallegos
Ralph Kristoffer B Gallegos
Nay Lin OoNay Lin Oo
Nay Lin Oo
Gopal KrishanGopal Krishan
Gopal Krishan
The study establishes two mathematical formulations to predict the pressure drop in a solid–liquid slurry flowing through a straight pipe. Employing the Eulerian–Eulerian RNG k-ε model, the computational investigation uses water as the carrier fluid and glass beads as solid particles. The analysis spans various particle sizes (d50 = 75–175 μm), volumetric concentrations (Cvf = 10–50%), and velocities (Vm = 1–5 m/s). The first model, developed using the MATLAB curve-fitting tool, is complemented by a second empirical equation derived through non-polynomial mathematical formulation. Results from both models are validated against existing experimental and computational data, demonstrating accurate predictions for d50 = 75–175 µm particles within a Reynolds number range of 20,000 ≤ Re ≤ 320,000.