1,721,527 research outputs found
PRELIMINARY HYDRAULIC PERFORMANCE MODEL FOR THE OPEN REV EVO PUMP
No full textThis brief technical note deals with a preliminary empirical model aimed at describing the hydraulic performance of a partial emission pump operating in the around of its own best efficiency point. In particular, the high-speed pump design internally named as OpenREV EVO is considered. Such design is the more recent evolution of the partial emission pump prototypes conceived to pressurise the fuel and oxidiser of a rocket engine to be installed in a European lunar lander, being developing by NAMMO UK under ESA funding. The aim of the technical note is to report the equations suggested as base for a mathematical model of the pump hydraulic performance.
To this purpose, the experimental data acquired by T4i were made dimensionless and approximated by polynomial curve fitting. The polynomials describing the dimensionless performance were finally rearranged to obtain dimensional equations of the pump pressure rise and hydraulic efficiency as a function of the pump mass flow rate, impeller rotational speed, and mass density of the working fluid. The results show the dimensional maps of the 45mm diameter OpenREV EVO prototype in the operation with the fuel and the oxidiser, as obtained using the presented equations, superimposed to the 50%, 100% and 117% nominal operation point requirements
A new practical approach to the design of industrial axial fans: Tube-axial fans with very low hub-to-tip ratio
No full textThis paper presents a simple but complete design method to obtain arbitrary vortex design tube-axial fans starting from fixed size and rotational speed. The method couples the preliminary design method previously suggested by the authors with an original revised version of well-known blade design methods taken from the literature. The aim of this work is to verify the effectiveness of the method in obtaining high-efficiency industrial fans. To this end, the method has been applied to a 315mm rotor-only tube-axial fan having the same size and rotational speed, and a slightly higher flow rate coefficient, as another prototype previously designed by the authors, which was demonstrated experimentally to noticeably increase the pressure coefficient of an actual 560mm industrial fan. In contrast, no constraints are imposed on the hub-to-tip ratio and pressure coefficient. The new design features a hub-to-tip ratio equal to 0.28 and radially stacked blades with aerodynamic load distribution corresponding to a roughly constant swirl at rotor exit. The ISO-5801 experimental tests showed fan efficiency equal to 0.68, which is 6% higher than that of the previous prototype. The pressure coefficient is lower, but still 12% higher than that of the benchmark 560mm industrial fan
Studio e progetto di un impianto di potenza innovativo operante a CO2 per il recupero di energia da flussi di calore industriali di scarto a medio-bassa temperatura
No full textHYDRAULIC PERFORMANCE MODEL FOR THE OPEN REV EVO PUMP
No full textThis technical note presents the empirical model describing the hydraulic performance of the high-speed pump design internally named as OpenREV EVO. The latter is the more recent evolution of the partial emission pump prototypes conceived to pressurise the fuel and oxidiser of a rocket engine to be installed in a European lunar lander, being developing by NAMMO UK under ESA funding. The aim of the technical note is to update and extend to the entire pump operation range the equations suggested in a previous note as base for a mathematical model of the pump hydraulic performance in operation around its best efficiency point.
To this purpose, additional experimental data acquired by T4i for pump operation up to the maximum flow rate were included in the data set used to define an appropriate polynomial curves fitting model of the dimensionless pump performance parameters. The revised model incorporates corrections accounting for the effects of the Reynolds number in order to obtain as output reliable values of the pump pressure rise and hydraulic efficiency as a function of the pump mass flow rate, impeller rotational speed, and molecular properties of the working fluid. The model was used to build the dimensional maps of the 45mm diameter OpenREV EVO prototype in operation with the fuel and the oxidiser. To further exploit the capabilities of the model, the performance maps expected by the OpenRev EVO prototype if manufactured with a 40mm diameter impeller are presented as well
Utilizzo del codice MULTALL nel progetto preliminare di turbine radiali con cassa a spirale priva di palette distributrici
No full textPreliminary design of radial turbomachines is supported by “single-channel” CFD models, ideal for design concepts comparison. Unfortunately, these models do not suit non-periodic domain calculations like those of turbines with vaneless spiral casings. A new approach that makes such domains periodic was implemented in the open-source code MULTALL and validated against non-periodic-domain results of state-of-the-art commercial codes
A New Practical Approach to the Design of Industrial Axial Fans: Part I — Tube-Axial Fans with Very Low Hub-to-Tip Ratio
No full textThis paper presents a simple but complete design method to obtain arbitrary vortex design tube-axial fans starting from fixed size and rotational speed. The method couples the preliminary design method previously suggested by the authors ago with an original revised version of well-known blade design methods taken from the literature. The aim of this work is to verify the effectiveness of the method in obtaining high efficiency industrial fans. To this end, the method has been applied to a 315mm rotor-only tube-axial fan having the same size and rotational speed, and a slightly higher flow rate coefficient, as another prototype previously designed by the authors, which was demonstrated experimentally to noticeably increase the pressure coefficient of an actual 560mm industrial fan. In contrast, no constraints are imposed on the hub-to-tip ratio and pressure coefficient. The new design features a hub-to-tip ratio equal to 0.28 and radially stacked blades with aerodynamic load distribution corresponding to a roughly constant swirl at rotor exit. The ISO-5801 experimental tests showed a fan efficiency equal to 0.68, which is 6% higher than that of the previous prototype. The pressure coefficient is lower, but still 12% higher than that of the benchmark 560mm industrial fan
Selection of the pump type for the propellants of the high-performance engine of a European lunar lander
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