https://orcid.org/0000-0002-8772-0988
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Abstract
The input power to a centrifugal pump is optimized by changing the impeller blade exit angle. In the optimization, blade exit angles of three meridional profile layers are selected as the design variables, while pump shaft power and head developed are the multi-objective optimization functions obtained through a surrogate model. A multi-objective genetic algorithm is used to find the optimum design point. Computational fluid dynamics simulations are performed to solve Reynolds-averaged Navier–Stokes equations using a shear-stress transport turbulence model for the closure term. Manipulation of the impeller blade angle profile affects both shaft power and efficiency without affecting the head at the best efficiency point, corresponding to a mass flow rate of 1.75 kg/s. The optimum design point of the pump impeller shows an enhancement (>10%) in pump efficiency. Improved flow separation near the trailing edge of the impeller blade and uniform blade loading decreases the input power required at the shaft of the pump impeller.
Acknowledgement
The authors are thankful to their institutes for providing laboratory facilities to facilitate the research work.
Disclosure statement
No potential conflict of interest was reported by the authors.
Nomenclature
| Abbreviations | = | |
| BEP | = | best efficiency point |
| CFD | = | computational fluid dynamics |
| DoE | = | design of experiments |
| EXP | = | experimental centrifugal pump |
| GIT | = | grid independency test |
| KRG | = | kriging |
| LE | = | leading-edge |
| LHS | = | Latin hypercube sampling |
| MOGA | = | genetic algorithm |
| OPT | = | optimized pump model |
| RANS | = | Reynolds-averaged Navier–Stokes |
| RBF | = | radial basis function |
| REF | = | reference pump design |
| RSA | = | response surface approximation |
| SST | = | shear-stress transport |
| TE | = | trailing-edge |
| WTA | = | weighted average |
| Symbols | = | |
| b | = | blade width (mm) |
| D | = | diameter (mm) |
| g | = | acceleration due to gravity (m/s2) |
| i,j | = | integer value 1,2, … |
| I | = | current consumed (A) |
| k | = | turbulence kinetic energy (J) |
| M | = | power consumed by the pump (W) |
| = | mass flow rate (kg/s) | |
| N | = | impeller speed (rpm) |
| P | = | power (W) |
| p | = | pressure (Pa) |
| Q | = | volume flow rate (m3/s) |
| Re | = | Reynolds number |
| r | = | radius (m) |
| s | = | strain rate tensor |
| T | = | torque (N-m) |
| t | = | blade thickness (mm) |
| v | = | relative velocity (m/s) |
| w | = | weighing function |
| x | = | decision variable |
| avg | = | average |
| del | = | delivery |
| in | = | input |
| out | = | output |
| th | = | theoretical |
| 1 | = | inlet |
| 2 | = | outlet |
| Greek symbols | = | |
| β | = | blade angle (degree) |
| ϵ | = | rate of kinetic energy dissipation (m2/s3) |
| η | = | efficiency |
| ϕ | = | phase angle between voltage and current (rad) |
| μ | = | dynamic viscosity of fluid (Ns/m2) |
| ρ | = | density of fluid (kg/m3) |
| τ | = | stress tensor (N/m2) |
| ω | = | angular speed (rad/s) |