In order to make centrifugal blowers environmentally friendly, machines with a lighter weight and a more compact size are required. Thus, the axial length of the machine needs to be minimized within ...the diameter limit. However, in the design methodology, losses and thermal study become very significant; thus, losses increase significantly to achieve the desired output power when the volume is excessively reduced. Moreover, due to the machine’s compact size, heat is concentrated rapidly without adequate cooling. It might lead to a temperature rise of the critical part of the machine above the safe limit, such as winding, thereby affecting its lifespan. This study considers the 225 kW high-speed permanent magnet synchronous machine (HSPMSM) with the forced air cooling axial ventilation system (FACAVS) used in centrifugal blower applications. Firstly, four different analytical models (A2–A5) in the electromagnetic analysis are derived by minimizing the initial machine’s (A1) axial length to achieve a lighter weight and more compact size with better electromagnetic performance. The best among analytical models is chosen as the A4 model with a lighter weight and a more compact structure in addition to higher torque density than A1, A2, and A3 models, and higher efficiency than A1, A2, A3, and A5 models by HSPMSM’s, optimal geometric design, and optimal material choice, respectively. Secondly, LPTN is designed to predict the entire analytical model’s thermal behavior in the thermal analysis. Investigation shows that winding temperature rises from the A4 model is maintained below winding insulation by the determined optimal axial ventilation parameters from the sensitivity analysis. Finally, different analytical models are prototyped and tested. The comparisons between predicted electromagnetic performance, winding temperature rise, and test results were carried out, and the results were found to agree with each other consistently.
This study aims towards the development of an optimised design of a centrifugal blower consisting of various fan ribs, based on performance assessments following changes in the shape of its internal ...components. Various components, such as the external cases and the rotating fan ribs placed in a variety of operating conditions, are evaluated numerically and experimentally. Evaluation is based on performance parameters, including the inlet and outlet pressures, flow rate, torque, and power of the centrifugal fan. The numerical analysis suggests that the combination of the multiple rotating frame method and the standard k-ε turbulence model was appropriate for simulation of the internal flow characteristics and for power prediction. The numerical results were compared with tests under carefully designed experimental conditions. Based on the results and depending on the exit shape of the fan, the flow rate gradually increased to a value 7% higher than the existing model. The experimental and the numerical calculation results were in good agreement, particularly at the exit boundary condition at atmospheric pressure. In addition, among the four different impellers studied, the fan type with forward-curved fan ribs was associated with the best performance, reaching a maximum flow rate of 2.2 m3/min and a torque of 0.09N⋅m.
•We performed an optimized design of a centrifugal blower with various fan ribs.•We examine the effects of the internal components of the fan on the surface pressure variation.•In-situ measurements are carefully designed to make a proper tendency.•The calculations are consistent with experiment.•The forward-curved fan ribs has the best performance.
This study presents an investigation on iron loss and start-up ability of a 1.5 kW output power with rated speed 5850 r/min 6/2 switched reluctance machine (SRM), which is used as a prime motor to ...directly drive centrifugal blower. Two winding connection types of the SRM are investigated, including the symmetrical magnetic topology (SyMT) and asymmetrical magnetic topology (ASyMT). The two types are proposed to settle poor self-start ability of the 6/2 SRM and high iron loss density of high-speed SRM. According to the simulation results, the SyMT has merit of self-start ability, i.e. no risk of start-up failure, whereas the ASyMT has advantage of low iron loss, i.e. low iron loss density on stator and rotor. Prototypes are manufactured to confirm and verify the predicted results and the test results prove the correctness of the analyses.
This paper focus on the effect of volute tongue clearance variation on the performance of backward-curved blades centrifugal blower. The four types of casings of the centrifugal blower with different ...volute tongue clearances of 6%, 8%, 10% and 12.5% of impeller diameter were used for numerical and experimental analysis. Computational fluid dynamics model was developed for for the numerical analysis based on experimental setup. Reynolds-averaged Navier-Stokes equations with the standard k-ε turbulence model were discretized with finite volume approximations. The Numerical results were validated with the experimental results by using IS: 4894-1987. The performance parameters such as total pressure, efficiency and flow rate of the blower were calculated. The results show that the volute tongue clearance has a significant effect on the performance of centrifugal blower and these parameters increases with decrease in volute tongue clearances.
Recently, it has become more important to develop vacuum cleaners which achieve both high suction power and low noise along with comfortable sound quality. To reduce the noise of centrifugal blowers, ...the authors investigated the pressure fluctuation in vaned diffusers using unsteady pressure measurement and compressible flow simulation. From the tracking analysis of the results of noise, it was confirmed that the rotational speed at which the pressure fluctuation in diffuser becomes maximum matches a resonance rotational speed. The pressure fluctuation in the diffuser has a node at the downstream of the overlapped region at any resonance rotational speed. On the other hand, the node position near the inlet of the overlapped region and the amplitude of the pressure fluctuation depend on the resonance rotational speed. Furthermore, it was revealed that stationary wave modes were dominant in the pressure fluctuation and governed the positions of the maximum and minimum pressure fluctuations along the flow direction.
In order to keep airship shape and realize desired performance during the course of landing safely from 20-km altitude, a specific blower is needed to be designed, and its characteristics should be ...analyzed. The CFturbo software is used to design the stratospheric blower. The performance of the designed stratospheric blower is calculated by computational fluid dynamics software PumpLinx simulation. Then, the performance of the blower at different altitudes is analyzed by simulation. It is shown that the designed stratospheric blower can basically meet the requirements of the semirigid airship of 160 m in length. The blower can make the airship land safely, and its efficiency can reach about 77% in the stratosphere. As the altitude decreases, the efficiency and volume flow (at different heights) of the blower gradually decrease. In addition, the sensitivity of different geometric parameters to the efficiency is analyzed, which can provide a reference for the optimization design of the stratospheric blower.
In the present study, a computational analysis of the flow in a centrifugal blower is carried out to predict a performance and to explain noise characteristics of the blower. Unsteady, 3D ...Navier-Stokes equations were solved with k-ε turbulence model using CFX software. CFD results were compared with the experimental data that is acquired from an experiment conducted with the same blower. The pressure fluctuation in the blower was transformed into the frequency domain by Fourier decomposition to find the relationship between flow behaviors and noise characteristics. Sound pressure level (SPL) which is obtained from wall pressure fluctuation at impeller outlet represents relative overall sound level of the blower well. Sound spectra show that there are some specific peak frequencies at each mass flow rate and it can be explained by flow pattern. KCI Citation Count: 0
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