https://orcid.org/0000-0001-6776-6367
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ABSTRACT
Energy consumption and economic growth are strongly linked. In connection, great emphasis is nowadays placed on the accuracy and efficiency of machines and measuring equipment. This study compares the effect of surface roughness on airflow through a gas ejector and a centric orifice plate. Both devices are made from the same material but using two different methods of manufacturing, conventional and additive manufacturing. The study compares, experimentally and with numerical simulation, the subcritical ejector by adjusting the distance between the nozzle outlet and the mixing chamber outlet in the range of 16.9 mm, during the primary inlet pressure control from 10 to 50 kPa. The orifice is evaluated experimentally for different pressures from 0.6 to 7 bar(g). The study evaluates the level of substitutability of conventionally manufactured devices by those produced using the additive method. At design condition, the additively manufactured ejector exhibits a 12.97% lower ejection coefficient, i.e. lower effectivity. After control optimization, the decrease is reduced to 11.66%. For the additively manufactured orifice, the measured value of the pressure difference at nominal parameters deviated by 2.17%. In the case of the orifice, substitution is possible, assuming the calibration, but the orifice has a higher-pressure loss.
Highlights
Various manufacturing methods are investigated via experiment
CFD analysis for surface roughness was applied
The additively manufactured ejector exhibits a 12.97% lower ejection coefficient
Additively manufactured centric orifice pressure difference deviated by 2.17%
Centric orifices are interchangeable with necessary calibration
Nomenclature
| c | = | Velocity, [m·s−1] |
| Coutnozzle | = | Nozzle outlet velocity, [m·s−1] |
| c2 | = | Outlet velocity, [m·s−1] |
| Cs | = | Roughness constant [-] |
| d0 | = | Suction pipe diameter, [m] |
| d1 | = | Nozzle entrance diameter, [m] |
| d2 | = | Nozzle exit diameter, [m] |
| d3,4 | = | Mixing chamber diameter, [m] |
| d5 | = | Diffuser exit diameter, [m] |
| h | = | Distance of the nozzle mouth to the mixing chamber inlet, [m] |
| Ksg | = | Sand Grain Roughness Height, [m] |
| L1 | = | Nozzle length, [m] |
| L2 | = | Mixing chamber length, [m] |
| Special characters | = | |
| Δp | = | Differential pressure, [Pa] |
| Δp1 | = | Inlet differential pressure, [Pa] |
| Δp2 | = | Outlet differential pressure, [Pa] |
| Subscripts | = | |
| 0 | = | Secondary medium/Suction |
| 1 | = | Inlet/Primary medium In/Nozzle |
| 2 | = | Outlet, Exit/Mixing chamber |
| 3 | = | Diffuser |
| Abbreviations | = | |
| BV | = | Ball valve |
| CFD | = | Computational fluid dynamics |
| CNV | = | Conventionally manufactured |
| DN | = | Diameter nominal |
| EM | = | Electric engine |
| FSR | = | full-scale range |
| GUM | = | Guide to the Expression of Uncertainty in Measurement |
| GV | = | Gate valve |
| L3 | = | Diffuser length, [m] |
| = | Mass flow of the secondary medium, [kg·s−1] | |
| = | Mass flow of the primary medium, [kg·s−1] | |
| p | = | Pressure, [Pa] |
| p1 | = | Inlet pressure, [Pa] |
| pd | = | Network (system) relative pressure, [Pa] |
| Ra | = | Arithmetic mean deviation, [m] |
| T1 | = | Inlet temperature, [K] |
| U | = | Function of the calculated value, [-] |
| uA | = | Standard uncertainties type A, [-] |
| uB | = | Standard uncertainties type B, [-] |
| uC | = | Combined standard uncertainty, [-] |
| = | Volume flow at Prandtl probe, [m3·s−1] | |
| Δu | = | Total uncertainty, [-] |
| Δy | = | Uncertainty of the input value, [-] |
| ε | = | Ejector is its ejection coefficient, [-] |
| 3,4 | = | Mixing chamber equality |
| 5 | = | Diffuser exit |
| d | = | Network, System |
| PR | = | Prandtl probe |
| H | = | Pressure hose |
| MT | = | Meter run |
| PBF | = | powder bed fusion |
| R | = | Pipe reduction |
| SC | = | Screw compressor |
| PN | = | Pressure nominal |
| 3D | = | Additively manufactured |
Acknowledgements
The study has been written in connection with the project “Innovative and additive manufacturing technology – New technological solutions for 3D printing of metals and composite materials (Reg. No.: CZ.02.1.01/0.0/0.0/17_049/0008407) financed by the structural funds of EU.”
The study has been written in connection with the project “REFRESH – Research Excellence For REgion Sustainability and High-tech Industries, (VP2), (Reg. No.: CZ.10.03.01/00/22_003/0000048) co-funded by the European Union.”
Disclosure statement
No potential conflict of interest was reported by the author(s).
Additional information
Notes on contributors
Zdeněk Šmída
Zdeněk Šmída works as an assistant professor at the Department of Energy Engineering, Faculty of Mechanical Engineering, VŠB-Technical University of Ostrava. His areas of interest are energy machines with an emphasis on flow devices and flow measurement. His interests are family, hiking, and computers.
Jan Výtisk
Jan Výtisk is a junior researcher at the Department of Energy Engineering, Faculty of Mechanical Engineering, VŠB-Technical University of Ostrava. Major specialization is the analytical environmental method of life cycle assessment of a product, technology, and service
Marek Jadlovec
Marek Jadlovec is a junior researcher at the Department of Energy Engineering, Faculty of Mechanical Engineering, VŠB-Technical University of Ostrava. Major specialization is the heat and mass transfer, and behavior of energy machines.
Roman Lukeš
Roman Lukeš is a Ph.D. student at the Department of Energy Engineering, Faculty of Mechanical Engineering, VŠB-Technical University of Ostrava. He specializes in energy machines and phenomena related to them.
Stanislav Honus
Stanislav Honus works as the head of the Department of Energy Engineering at the Faculty of Mechanical Engineering of VŠB-Technical University of Ostrava. His areas of interest are alternative fuels and heat and mass transfer.
Mojmír Vrtek
Mojmír Vrtek works as an associate professor at the Department of Energy Engineering, Faculty of Mechanical Engineering, VŠB-Technical University of Ostrava. His areas of interest are mainly cooling equipment and cycles, wind turbines, and solar panels
Bassel Nesser
Bassel Nesser is a Ph.D. student at the Department of Energy Engineering, Faculty of Mechanical Engineering, VŠB-Technical University of Ostrava. He specializes in energy machines, mainly wind turbines.