Regenerative Pump Research Articles

Performance enhancement of a pump impeller using optimal design method

This paper presents the performance evaluation of a regenerative pump to increase its efficiency using optimal design method. Two design parameters which define the shape of the pump impeller, are introduced and analyzed. Pump performance is evaluated by numerical simulation and design of experiments(DOE). To analyze three-dimensional flow field in the pump, general analysis code, CFX, is used in the present work. Shear stress turbulence model is employed to estimate the eddy viscosity. Experimental apparatus with an open-loop facility is set up for measuring the pump performance. Pump performance, efficiency and pressure, obtained from numerical simulation are validated by comparison with the results of experiments. Throughout the shape optimization of the pump impeller at the operating flow condition, the pump efficiency is successfully increased by 3 percent compared to the reference pump. It is noted that the pressure increase of the optimum pump is mainly caused by higher momentum force generated inside blade passage due to the optimal blade shape. Comparisons of pump internal flow on the reference and optimum pump are also investigated and discussed in detail.

Noise optimization of a regenerative automotive fuel pump

The regenerative pump used in automotive is facing a noise problem. To understand the mechanism in detail, Computational Fluid Dynamics (CFD) and Computational Acoustic Analysis (CAA) together were used to understand the fluid and acoustic characteristics of the fuel pump using ANSYS-CFX 15.0 and LMS Virtual. Lab Rev12, respectively. The CFD model and acoustical model were validated by mass flow rate test and sound pressure test, respectively. Comparing the computational and experimental results shows that sound pressure levels at the observer position are consistent at high frequencies, especially at blade passing frequency. After validating the models, several numerical models were analyzed in the study for noise improvement. It is observed that for configuration having greater number of impeller blades, noise level was significantly improved at blade passing frequency, when compared to that of the original model.

A plane-to-plane comparison of Common Averaged vs. POD patterns of Time-Resolved Stereo-PIV data within a pump

The purpose of the present study addresses to identify and compare different coherent flow patterns gathered by means of Time-Resolved Stereo Particle Image Velocimetry (TR-SPIV) within the side channel of a Regenerative Flow Pump (RFP). Common Average approaches, as well as a Proper Orthogonal Decomposition (POD) are applied on multiple 2D planes spanning over the third dimension for a single Operating Point. By comparing the strongest patterns for different measurement planes in terms of structure and energy, it is possible to gain new insights into the complex flow dynamics within the side channel, enabling to uncover the interplay of different planes, therefore the derivation of the 3D character of the flow dynamics. Multiple planes along the height of the side channel of the pump are discussed.

A regenerative elastocaloric heat pump

A large fraction of global energy use is for refrigeration and air-conditioning, which could be decarbonized if efficient renewable energy technologies could be found. Vapour-compression technology remains the most widely used system to move heat up the temperature scale after more than 100 years; however, caloric-based technologies (those using the magnetocaloric, electrocaloric, barocaloric or elastocaloric effect) have recently shown a significant potential as alternatives to replace this technology due to high efficiency and the use of green solid-state refrigerants. Here, we report a regenerative elastocaloric heat pump that exhibits a temperature span of 15.3 K on the water side with a corresponding specific heating power up to 800 W kg−1 and maximum COP (coefficient-of-performance) values of up to 7. The efficiency and specific heating power of this device exceeds those of other devices based on caloric effects. These results open up the possibility of using the elastocaloric effect in various cooling and heat-pumping applications. Although heating and cooling consume a large fraction of global energy, current technologies are not energy efficient. Tusek et al. report an elastocaloric heat pump with active regeneration that can outperform other caloric-based cooling and heat-pumping devices.

Effect of suction side blade profile on the performance of a side channel pump

Due to the centrifugal effect of the radial impeller, side channel pumps are a kind of regenerative pumps that provide high head at low flow rate. The geometry of the impeller affects flow patterns and energy conversion directly, greatly influencing the performance of side channel pumps. To investigate the effect of blade profile for suction side on the performance of a side channel pump, three different base angles of 10°, 20°, and 30°, respectively, on the blade suction side were discussed and analyzed both with numerical and experimental methods. The hydraulic performance, exchange mass flow, and velocity vectors were discussed in detail. The numerical work was validated by the comparison between the simulated result and tested result. The results show that the hydraulic performance of the impeller with 30° angle is the best one of the three impellers, especially for head performance. The evaluation method based on exchanged mass flow also confirms that the performance of the side channel pump can be improved by increasing the angle on the suction side of the blade. In addition, the radial vortex on the impeller flow passage has negative effect on the performance of the side channel pump. However, the axial vortex among the impeller and side channel directly affects the energy conversion and has a beneficial effect on the performance of the pump. The results could be used to modify the design models and conclude the effect of blade shapes on the performance of a side channel pump.

Flow Pattern Analysis and Performance Improvement of Regenerative Flow Pump Using Blade Geometry Modification

Regenerative pump is a low specific speed and rotor-dynamic turbomachine capable of developing high heads at low flow rates. In this paper, a numerical study has been carried out in order to investigate the effect of blade angle on the performance of a regenerative pump. Two groups of impellers were employed. The first type has symmetric angle blades with identical inlet/outlet angles of ±10°, ±30°, and ±50° and the second group has nonsymmetric angle blades in which the inlet angle was set to 0° and six different angles of ±10°, ±30°, and ±50° were designed for the outlet of the blades. A total of 12 impellers, as well as primary radial blades impeller, were investigated in this study. The results showed that all forward blades have higher head coefficients than radial blades impeller at design flow coefficient. It was found that regenerative pumps with symmetric angle forward blades have better performance than other types. Also, it is worth mentioning that the highest head coefficient and efficiency occur at angle+10<β<+30of symmetric angle blades. It was found that the maximum efficiency occurs at angle of +15.5° by curve fitting to the data obtained from numerical simulations for symmetric angle forward blades.

Enhancement of Regenerative Pump Performance using Rapid Manufacturing Techniques

This research article presents a technique of rapid manufacturing used in the improvement of a regenerative pump impeller. Regenerative pumps are the subject of increased interest in industry. The technique of Rapid manufacturing was used to make complex impeller blade profiles for testing as part of a regenerative pump optimization process such as few modified impeller blade profile, relative to the standard radial configuration, was manufactured by using Selective Laser Sintering for experimental testing method. The difficulty of the modified blade profiles would normally require the use of costly CNC machining with five axis capability. The manufacture of the complex blade profiles using conventional milling techniques is a considerable challenge for skilled machinists in industries.

Polarization-Independent All-Optical Regenerator for DPSK Data

We demonstrate polarization-independent simultaneous all-optical phase-preserving amplitude regeneration and wavelength conversion of NRZ differential phase shift keying (DPSK) data by four-wave mixing (FWM) in a semiconductor optical amplifier (SOA). The dependence upon polarization state of the signals is eliminated by using a co-polarized dual-pump architecture. Investigation on the regenerative capability vs. pumps detuning shows significant BER threshold margin improvement over 6 nm conversion range.

재생 펌프의 날개 각도에 따른 성능 변화에 관한 실험적 연구

The regenerative pump is a kind of turbomachine which is capable of developing high pressure rise at relatively lower flow rates compared to the centrifugal and axial pumps. Although the efficiency of regenerative pumps is much lower than other turbomachines, still they have been widely used in many industrial applications for working at low specific speeds. There are some theoretical models to analysis the pump performance, however, the effect of the blade angle on the pump performance has not been covered in any model to date. In the present study, experimental study on the regenerative pump performance according to the impeller blade angle and its shape has been carried out. The straight radial blades with forward, backward and chevron blades which have inclined angles of 15°, 30° and 45° were tested. The pump performance characteristics as the pressure head, efficiency were obtained depending on the flow rate for every impeller, and their results, expressed in appropriate non-dimensional coefficients, were compared and analysed in detail. From the experimental results, it was found that the pressure head and the efficiency depend strongly on the blade angles as well as the blade type. These experimental data has made it possible to better understand the effects of the blade angle on the pump performance, and widen the applicability of the current performance analysis and design models with including the effect of blade angles.

Experimental study on the effect of blade angle on regenerative pump performance

The regenerative pump is a kind of turbomachine that is capable of developing a high pressure rise at relatively low flow rates compared to the centrifugal and axial pumps. Although the efficiency of regenerative pumps is much lower than other turbomachines, they have still been widely used in many industrial applications for high heads at low flow rates. There are a few theoretical models to analyze the performance of regenerative pumps, though, the effect of the blade angle has not been included in any analysis model to date. In this study, the influence of the impeller blade angle and its shape on regenerative pump performance has been experimentally investigated. Straight blades with inclined blade angles of 0°, ± 15°, ± 30° and ± 45° were tested. In addition radial chevron impellers with chevron angles of 15°, 30° and 45° were also included in the present experiments. Hence a total of 10 blade configurations were examined. The pressure head, efficiency and the fluid temperature rise were measured at different flow rates and the results were expressed in appropriate non-dimensional coefficients. From the experimental results, it was found that the pressure head and the efficiency strongly depend on the blade angles as well as the blade geometry. Among all blade configurations tested in this study, the chevron blade exhibited the highest head with reasonably good efficiency. The comparative study shows that there is an optimum chevron angle of around 30° that yields the best performance. These experimental data may be used to include the effect of blade angles in the current performance analysis and design models to widen their applicability.

파이프형 원심펌프의 성능특성에 관한 실험적 연구

The positive displacement pump and the regenerative pump are widely used in the range of low specific speed, [rpm, m3/min, m]. The positive displacement pump is not suitable for miniaturization and operation in high rotational speed. The regenerative pump has a problem with large leakage flow and low efficiency. While the centrifugal pump has advantages of high efficiency, miniaturization and high rotational speed, efficiency drops sharply with decrease in specific speed. Therefore the purpose of this study is to design a new type of centrifugal pump that has advantages of centrifugal pumps in operation in low specific speed. The name of this new type of pump was called `Pipe type centrifugal pump`, since the flow path through the impeller is simple circular pipe. Due to the simple shape of impeller, the manufacturing process is simple and cost is low. There is strong jet flow at the outlet of the impeller. This jet induces flow path loss, meridional dynamic pressure loss and mixing loss. Large disk friction makes the efficiency be limitted in the range of low specific speed. Even though the loss and the low efficiency, `Pipe type centrifugal pump` represents stable performance, affordable pressure ratio and efficiency better than that of other low specific speed pumps.

The quasi-cavity performance in a back-reflection regenerative pumping system for high power disk laser systems

A quasi-cavity equipped on both sides with mirrors that have a transparent hole at their centers is used for a back-reflection regenerative pumping system for a thin-disk solid state laser instead of the multipass pumping system. We have investigated thermo-optical and thermo-mechanical properties of the quasi-cavity by employing finite element analysis (FEA) numerical method in a cylindrical and a rectangular quasi-cavity. Temperature, displacement distribution and variation of refractive index of the rectangular quasi-cavity in different pump powers have been calculated for several materials. We recommend a combination of diamond/YAG crystal in making quasi-cavity for better performance in high power quasi-end-pumped thin disk laser.

Design study of a regenerative pump using one-dimensional and three-dimensional numerical techniques

Regenerative pumps are low cost, compact and able to deliver high heads at low flowrates. Furthermore with stable performance characteristics they can operate with very small NPSH. The complexity of the flowfield is a serious challenge for any kind of mathematical modelling. This paper compares an analytical and numerical technique of resolving the performance for a new regenerative pump design. The performance characteristics computed by a CFD approach and a new one-dimensional model are compared and matched to experimental test results. The approaches of both modelling techniques are assessed as potential design tools. The approaches are shown to not only successfully resolve the complex flowfield within the pump; the CFD is also capable of resolving local flow properties to conduct further refinements. The flow field is represented by the CFD as it has never been before. A new design process is suggested. The new regenerative pump design is considered with a comparable duty centrifugal pump, proving that for many high head low flowrate applications the regenerative pump is a better choice.

A One-Dimensional Numerical Model for the Momentum Exchange in Regenerative Pumps

The regenerative pump is a rotor-dynamic turbomachine capable of developing high heads at low flow rates and low specific speeds. In spite of their low efficiency, usually less than 50%, they have found a wide range of applications as compact single-stage pumps with other beneficial features. The potential of a modified regenerative pump design is presented for the consideration of the performance improvements. In this paper the fluid dynamic behavior of the novel design was predicted using a one-dimensional model developed by the authors. Unlike most one-dimensional models previously published for regenerative pumps, the momentum exchange is numerically computed. Previous one-dimensional models relied on experimental data and correction factors; the model presented in this paper demonstrates an accurate prediction of the pump performance characteristics without the need for correction with experimental data. The validity of this approach is highlighted by the comparison of computed and measured results for two different regenerative pump standards. The pump performance is numerically assessed without the need of correction factors or other experimental data. This paper presents an approach for regenerative pumps using a physically valid geometry model and by resolving the circulatory velocity in the peripheral direction.

Design optimisation of a regenerative pump using numerical and experimental techniques

PurposeRegenerative pumps are the subject of increased interest in industry as these pumps are low‐cost, low‐specific speed, compact and able to deliver high heads with stable performance characteristics. However, these pumps have a low efficiency (35‐50 per cent). The complex flow field within the pumps represents a considerable challenge to detailed mathematical modelling. Better understanding of the flow field would result in improvement of the pump efficiency. The purpose of this paper is to consider a numerical and experimental analysis of a regenerative pump to simulate the flow field and math pump performance.Design/methodology/approachThis paper outlines the use of a commercial computational fluid dynamics (CFD) code to simulate the flow field within the regenerative pump and compare the CFD results with new experimental data. A novel rapid manufacturing process is used to consider the effect of impeller geometry changes on the pump efficiency.FindingsThe CFD results demonstrate that it is possible to represent the helical flow field for the pump which has only been witnessed in experimental flow visualisation until now. The CFD performance results also demonstrate reasonable agreement with the experimental tests.Research limitations/implicationsThe design optimisation only considers a number of blade geometry changes. The future work will consider a much broader spectrum of design modifications which have resulted in efficiency improvements in the past.Practical implicationsThe ability to use CFD modelling in conjunction with rapid manufacturing techniques has meant that more complex geometry configurations can now be assessed with better understanding of the flow field effects and resulting efficiency.Originality/valueThis paper presents new flow field visualisation and better correlation to the matched performance than the current limited mathematical models. This paper also presents a novel method for rapid manufacturing of the pump impeller.

Development of a regenerative pump impeller using rapid manufacturing techniques

PurposeThe purpose of this paper is to present a method of rapid prototyping (RP) used in the development of a regenerative pump impeller. RP technology was used to create complex impeller blade profiles for testing as part of a regenerative pump optimisation process. Regenerative pumps are the subject of increased interest in industry.Design/methodology/approachTen modified impeller blade profiles, relative to the standard radial configuration, were evaluated with the use of computational fluid dynamics (CFD) and experimental testing. Prototype impellers were needed for experimental validation of the CFD results. The manufacture of the complex blade profiles using conventional milling techniques is a considerable challenge for skilled machinists.FindingsThe complexity of the modified blade profiles would normally necessitate the use of expensive computer numerically controlled machining with five‐axis capability. With an impeller less than 75 mm in diameter with a maximum blade thickness of 1.3 mm, a rapid manufacturing technique enabled production of complex blade profiles that are dimensionally accurate and structurally robust enough for testing.Research limitations/implicationsAs more advanced RP machines become available in the study in the coming months, e.g. selective laser sintering, the strength of the parts particularly for higher speed testing will improve and the amount of post processing operations will reduce.Practical implicationsThis technique offers the possibility to produce components of increased complexity whilst ensuring quality, strength, performance and speed of manufacture.Originality/valueThe ability to manufacture complex blade profiles that are robust enough for testing, in a rapid and cost effective manner is proving essential in the overall design optimisation process for the regenerative pump.

アキシャルセルフベアリングモータを用いた小型ポンプのポンプ特性(機械力学,計測,自動制御)

For the spread of small fuel cells, it is important to improve the performance of peripheral devices including fuel supply pumps, and to lower a price of them. A miniature diaphragm pump can utilize as a fuel supply pump, however it has many problems. Therefore, we propose small regenerative pump using axial self-bearing motor. The unidirectional type Axial Self-Bearing Motor that has a function of producing motor torque and controlling axial position of the rotor enables miniaturization and reducing cost. In this paper, a structure of the pump and control system are introduced, and results of pump efficiency are shown.

Study for the Increase of Micro Regenerative Pump Head

The effect of inlet and outlet blade angles on a micro regenerative pump head was examined in experiments. The pump head was little increased by changing the blade angles compared with the original pump with the inlet and outlet blade angles of 0 degree. The effect of the axial clearance between the impeller and the casing on the pump head was also examined. The head was increased largely by decreasing the axial clearance. The computation of the internal flow was performed to clarify the cause of the increase of the pump head due to the decrease of the clearance. The local flow rate in the casing decreased as the leakage flow rate through the axial clearance decreased due to the decrease of the clearance. It was found that the larger head in the smaller clearance was just caused by the smaller local flow rate in the casing. In the case of the smaller clearance, the smaller local flow rate caused the smaller circumferential velocity near the front and rear sides of the impeller. This caused the increase of the angular momentum in the casing and the head.

Reynolds Number Effects on the Performance Characteristic of a Small Regenerative Pump

This paper studies the effect of the Reynolds number on the performance characteristics of a small regenerative pump. Since regenerative pumps have low specific speeds, they are usually applicable to small devices such as micropumps. As the operating Reynolds number decreases, nondimensional similarity parameters such as flow and head coefficients and efficiency become dependent on the Reynolds number. In this study, the Reynolds number based on the impeller diameter and rotating speed varied between 5.52×103 and 1.33×106. Complex three-dimensional flow structures of internal flow vary with the Reynolds numbers. The coefficients of the loss models are obtained by using the calculated through flows in the impeller. The estimated performances obtained by using one-dimensional modeling agreed reasonably well with the numerically calculated performances. The maximum values of flow and head coefficients depended on the Reynolds number when it is smaller than 2.65×105. The critical value of the Reynolds number for loss coefficient and maximum efficiency variations with Reynolds number was 1.0×105.

Effect of Internal Flow in Symmetric and Asymmetric Micro Regenerative Pump Impellers on Their Pressure Performance

The effect of symmetric and asymmetric micro regenerative pump impellers on their pressure performance was studied. The shut off head of the pump with the symmetric impeller was about 2.5 times as that with the asymmetric impeller. The computation of the internal flow was performed to clarify the cause of the increase of the head. It was found that the contribution of the angular momentum supply was larger than that of shear stress for the head development in both cases. The larger head and momentum supply in the case of the symmetric impeller were caused by larger recirculated flow rate and larger angular momentum difference between the inlet and outlet to the impeller. The larger recirculated flow rate was caused by smaller pressure gradient in the direction of recirculated flow. The decrease of the circumferential velocity in the casing was attributed to the smaller local flow rate in the casing.