Tesla Pump Research Articles

Multidisciplinary design and manufacturing of a Tesla pump prototype

To widen the range of hydraulic efficiencies of boundary layer pumps, a full design methodology has been proposed in order to identify critical issues for their performance and manufacturing. The methodology integrated a 2D numerical code, CFD and FEM analyses, coupled with manufacturing assessments as feedback mechanism. Considering budget constraints and in-house machining capabilities, a quick first prototype was produced. Analyses of the design are pointing out that the volute design initially chosen will not help to achieve an increase in the overall efficiency. The curves of head achieved with 2D and CFD are in agreement, but the latter determines the losses with larger accuracy, thus achieving lower values of head. The 2D model shows limits in the determination of the efficiency, effectively corrected by the CFD analysis. Critical parameters as disc thickness and gap between discs will require a more sophisticated assembly process and materials outsource. The proposed methodology could be used as a reference for the design and performance evaluation of this kind of turbomachinery in the future. The procedure lead to a prototype design, whose optimal efficiency slightly lower than 30 % was achieved at 5000 rpm with 0.3 mm disks gap.

Identifying the influence of number of blades and distance between blades on tesla pump characteristics

The main principle of the Tesla pump is to increase the shear stresses as a result of the rotation of the pump blades, and thus increase the kinetic energy of the fluid to form a mass flow. The types of mechanical pumps are many and the ways of their use are wide. Over the years, scientists have contributed to developing types of pumps to get the best pump efficiency. The rotational energy can be converted into a mass flow of the fluid that can be pumped. As the Tesla pump is one of the types that gives a wide impression of fluid mechanics, where the viscosity and shear stress of the fluid will be in the movement of the fluid particles and the formation of a centrifugal force that gives an active flow of the fluid. Tesla pump is one of the primitive pumps that can be modified to study this research paper and know the number of fins used and the optimal distance between them to obtain the best mechanical efficiency of the pump. Where the Tesla pump was designed with variable fins, 3, 6 and 11 fins were taken to compare them, and the distance between the fins was reduced from 10 mm to 5 mm with a change of 2.5 mm, where the changes that occur on the pump can be observed. Where the results proved that the value of the fins increases the flow velocity of the fluid, as the best case was at the fins number 11, where the flow velocity reached 13 m/s. As for the change of distance, it is an inverse relationship as the small distance between the fins impedes the movement of the fluid flow and thus reduces the value of the flow. In the case where the number of turbine blades is 11, shear stresses reached 401 Pa. Which is the best case compared to the rest of the cases. The mechanical movement of the water was significantly increased

Design and CFD Simulation of Tesla Pump

The need for high pump performance and efficiency continue to encourage the study of flow between two parallel co-rotating discs in multiple discs pump or turbine. Therefore, this study entails the design, construction and CFD simulation of a 3D Tesla pump model axisymmetric swirling flow in order to enhance the understanding of Tesla pump for future development. Method of solution entails designing and construction of a small prototype tesla pump and then using the design geometry and parameters to design and perform numerical simulation. The results of the numerical simulation were then analyzed. The result obtained indicates static pressure to have minimum value of -4.7791Pa at the outlet and 13.777Pa at the pump inlet and with velocity magnitude having minimum velocity of 0.00m/s and maximum velocity of 4.12m/s. The strength of the velocity was seen to be very high at the pump outlet. The analysis radial velocity showed minimum value of -0.508m/s and maximum value of 3.981m/s with the radial velocity vector being concentrated at the discs periphery and outlet. Model simulation results exhibited smooth pressure and velocity profiles. With the 3D simulation all flow variables are able to be predicted.

Topology optimization based on a two-dimensional swirl flow model of Tesla-type pump devices

Tesla pumps are composed of rotating disks (without blades) and are based on the boundary layer effect (i.e., viscous friction forces acting on the fluid and Coandă effect). The Tesla pump has various applications, however, the efficiency of its operation is quite low, which makes room for the optimization of its design. This way, novel configurations of devices based on this working principle can be developed. Thus, in this work, a Topology Optimization formulation is proposed to optimize the rotor of a Tesla-type pump device by using a 2D swirl flow model, which is a specific model that presents an axisymmetric flow with (or without) flow rotation around the axisymmetric axis. The 2D swirl laminar fluid flow modeling is solved by using the finite element method. A traditional material model is adopted by considering nodal design variables, and is extended to take into account the fact that the optimization is performed in a rotating reference frame and the relative tangential velocity behaves differently than the other velocity components (since the 2D swirl flow model is axisymmetric). A multi-objective function is defined in order to minimize energy dissipation and vorticity. An extra term is proposed to the vorticity function to reduce the generation of grayscale results. An interior point optimization algorithm (IPOPT) is applied to solve the optimization problem. Numerical results taking into account different aspects of the design of the rotor of a Tesla-type device are presented.

A Laminar Flow-Based Microfluidic Tesla Pump via Lithography Enabled 3D Printing.

Tesla turbine and its applications in power generation and fluid flow were demonstrated by Nicholas Tesla in 1913. However, its real-world implementations were limited by the difficulty to maintain laminar flow between rotor disks, transient efficiencies during rotor acceleration, and the lack of other applications that fully utilize the continuous flow outputs. All of the aforementioned limits of Tesla turbines can be addressed by scaling to the microfluidic flow regime. Demonstrated here is a microscale Tesla pump designed and fabricated using a Digital Light Processing (DLP) based 3D printer with 43 µm lateral and 30 µm thickness resolutions. The miniaturized pump is characterized by low Reynolds number of 1000 and a flow rate of up to 12.6 mL/min at 1200 rpm, unloaded. It is capable of driving a mixer network to generate microfluidic gradient. The continuous, laminar flow from Tesla turbines is well-suited to the needs of flow-sensitive microfluidics, where the integrated pump will enable numerous compact lab-on-a-chip applications.

PROSPECTS OF DISK PUMP FOR MECHANICAL CIRCULATORY SUPPORT IN CARDIAC SURGERY (REVIEW)

The need of circulatory support systems in the treatment of chronic heart failure is increasing constantly, as 20% of the patients on the waiting list die every year. Despite the great need for mechanical heart support systems, the use of available systems is limited by its expensiveness. In addition, there is no one system that is 100% responsible to all medical and technical requirements and that would be completely safe for patient. Therefore, further research in the field of circulatory support systems considering health and technical requirements is relevant. One of the new directions in the study are disc pumps of viscous friction for liquid transporting, based on the Tesla pump principle. The operation principle of such pumps is based on the phenomenon of the boundary layer which is formed on the disk rotating in a fluid. There are experimental studies of models with different variants of the rotor suspension, various forms and numbers of the disks, forms of the pump housing. However, none of the above samples was brought to clinical trials. Furthermore, despite the potential of that model there have been no pumps of similar type used so far in circulatory support systems. Published data provide a basis for further development and testing of the pump model and allow hoping for leveling a number of significant shortcomings of modern left ventricular bypass systems.

Application of CFD to model oil–air flow in a grooved two-disc system

The flow field of an open grooved two-disc system was studied. The system includes a rotating finite disc and a stationary finite disc. The rotating disc has radial grooves. The numerical results for the air–oil two-phase flow inside the open grooved two-disc system calculated by the CFD code FLUENT were proposed. The results are discussed and compared with the published test results. The results indicate that the groove affects the transitional characteristics from a single-phase flow to an air–oil two-phase flow of the flow field. In the same flow area, the radial oil flow coefficient is enhanced with a larger groove number. The oil mainly discharges through the groove and the air flows into the non-grooved area from the upstream side of the groove. The effects of the angular velocity on the oil volume fraction and the drag torque become greater when the disc is grooved. It is weakened in the high-velocity operations. The drag torque can be reduced by increasing the groove number in the same flow area. The axial force applied on the disc is gradually decreased with the increase of the angular velocity and becomes close to zero finally. The increase of the groove number reduces the maximum axial force. The results can be used for the optimisation of the Tesla pump and wet clutch.

Tesla-Based Blood Pump and Its Applications.

A continuous flow left ventricular assist device (LVAD) that the Penn State University has developed utilizes Tesla turbomachinery technology. Tesla pumping technology patented by Nikola Tesla in the early 20th century has multiple intriguing characteristics such as simpler manufacturing process, reduced turbulent-related stress, less cavitation due to viscous flow distribution over larger surface areas, and less hemolysis by smooth transition of fluid energy. We successfully tested the 1st version of the Penn State Tesla LVAD [1, 2]. We recently tested the 2nd version of the Tesla pump; to make the pump usable in a wide range of patients, the size of the pump was significantly reduced while trying to avoid any degradation of hemodynamic and hemolytic characteristics.Copyright © 2013 by ASME

Computational Fluid Dynamics Design and Analysis of a Passively Suspended Tesla Pump Left Ventricular Assist Device

This article summarizes the use of computational fluid dynamics (CFD) to design a novel suspended Tesla left ventricular assist device. Several design variants were analyzed to study the parameters affecting device performance. CFD was performed at pump speeds of 6500, 6750, and 7000 rpm and at flow rates varying from 3 to 7 liters per minute (LPM). The CFD showed that shortening the plates nearest the pump inlet reduced the separations formed beneath the upper plate leading edges and provided a more uniform flow distribution through the rotor gaps, both of which positively affected the device hydrodynamic performance. The final pump design was found to produce a head rise of 77 mm Hg with a hydraulic efficiency of 16% at the design conditions of 6 LPM through flow and a 6750 rpm rotation rate. To assess the device hemodynamics the strain rate fields were evaluated. The wall shear stresses demonstrated that the pump wall shear stresses were likely adequate to inhibit thrombus deposition. Finally, an integrated field hemolysis model was applied to the CFD results to assess the effects of design variation and operating conditions on the device hemolytic performance.

A passively suspended Tesla pump left ventricular assist device.

The design and initial test results of a new passively suspended Tesla type left ventricular assist device blood pump are described. Computational fluid dynamics (CFD) analysis was used in the design of the pump. Overall size of the prototype device is 50 mm in diameter and 75 mm in length. The pump rotor has a density lower than that of blood and when spinning inside the stator in blood it creates a buoyant centering force that suspends the rotor in the radial direction. The axial magnetic force between the rotor and stator restrain the rotor in the axial direction. The pump is capable of pumping up to 10 L/min at a 70 mm Hg head rise at 8,000 revolutions per minute (RPM). The pump has demonstrated a normalized index of hemolysis level below 0.02 mg/dL for flows between 2 and 9.7 L/min. An inlet pressure sensor has also been incorporated into the inlet cannula wall and will be used for control purposes. One initial in vivo study showed an encouraging result. Further CFD modeling refinements are planned and endurance testing of the device.

A multiple disk centrifugal pump as a blood flow device

A multiple disk, shear force, valveless centrifugal pump was studied to determine its suitability as a blood flow device. A pulsatile version of the Tesla viscous flow turbine was designed by modifying the original steady flow pump concept to produce physiological pressures and flows with the aid of controlling circuitry. Pressures and flows from this pump were compared to a Harvard Apparatus pulsatile piston pump. Both pumps were connected to an artificial circulatory system. Frequency and systolic duration were varied over a range of physiological conditions for both pumps. The results indicated that the Tesla pump, operating in a pulsatile mode, is capable of producing physiologic pressures and flows similar to the Harvard pump and other pulsatile blood pumps.