Design Optimization of a Wearable Artificial Pump-Lung Device With Computational Modeling

2012 ◽  
Vol 6 (3) ◽  
Author(s):  
M. Ertan Taskin ◽  
Tao Zhang ◽  
Katharine H. Fraser ◽  
Bartley P. Griffith ◽  
Zhongjun J. Wu
Keyword(s):  
Design Optimization ◽  
Performance Optimization ◽  
Hollow Fiber Membrane ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Design Parameters ◽  
Centrifugal Impeller ◽  
Damage Potential ◽  
Cardiopulmonary Support

The heart-lung machine has commonly been used to replace the functions of both the heart and lungs during open heart surgeries or implemented as extracorporeal membrane oxygenation (ECMO) to provide cardiopulmonary support of the heart and lungs. The traditional heart-lung system consists of multiple components and is bulky. It can only be used for relatively short-term support. The concept of the wearable artificial pump-lung is to combine the functions of the blood pumping and gas transfer in a single, compact unit for cardiopulmonary or respiratory support for patients suffering from cardiac failure or respiratory failure, or both, and to allow patients to be ambulatory. To this end, a wearable artificial lung (APL) device is being developed by integrating a magnetically levitated centrifugal impeller with a hollow fiber membrane bundle. In this study, we utilized a computational fluid dynamics based performance optimization with a heuristic scheme to derive geometrical design parameters for the wearable APL device. The configuration and dimensions of the impeller and the diffuser, the required surface area of fiber membranes and the overall geometrical dimensions of the blood flow path of the APL device were considered. The design optimization was iterated based on the fluid dynamic objective parameters (pressure head, pressure distribution, axial force acting on the impeller, shear stress), blood damage potential (hemolysis and platelet activation), and mass transfer (oxygen partial pressure and saturation). Through the design optimization, an optimized APL device was computationally derived. A physical prototype of the designed APL device was fabricated and tested in vitro. The experimental data showed that the optimized APL can provide adequate blood pumping and oxygen transfer over the range of intended operating conditions.

Detailed Hydrodynamic Study for Performance Optimization of a Combined Lift and Drag-Based Modified Savonius Water Turbine

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Mithinga Basumatary ◽  
Agnimitra Biswas ◽  
Rahul Dev Misra
Keyword(s):  
Performance Optimization ◽  
Operating Conditions ◽  
Hydrodynamic Performance ◽  
Design Parameters ◽  
Ansys Fluent ◽  
Orthogonal Experiments ◽  
Water Turbine ◽  
Hydrodynamic Study ◽  
Lift And Drag ◽  
Power Curves

Abstract A combined lift and drag (CLD) Savonius water turbine is an advanced form of Savonius water turbine that has higher efficiency than the latter. However, its detailed hydrodynamic performance optimization is still unexplored, which is important for its possible future commercialization. The objective of the present work is to perform a detailed hydrodynamic study for performance optimization of the CLD Savonius water turbine at low water speed (characteristic of river stream current) under different design and operating conditions. A parametric optimization using orthogonal experiments is first done to obtain the optimized values of all the contributing design parameters. It is then followed by a detailed computational fluid dynamics (CFD) investigation using ansys fluent software to optimize the hydrodynamic performance of the turbine at the selected design conditions under different operating tip speed ratios (TSRs). Detailed fluidic behaviors including boundary layer features, blade loading, and vorticity structures of the turbine are explored to obtain important performance insights, and power curves of the improved CLD design are also obtained. It is found that the optimized CLD Savonius water turbine has higher hydrodynamic performance than the earlier design of this turbine with a maximum coefficient of power obtained as 0.29 at TSR 0.8.

Numerical Investigation of the Euler Turbomachinery Equation and Analysis of the Impact of the Impeller Design on the Fan Performance by an Optimization Study

2019 ◽  
Author(s):  
Manuel Fritsche ◽  
Philipp Epple ◽  
Stefan Gast ◽  
Antonio Delgado
Keyword(s):  
Energy Conversion ◽  
Euler Equation ◽  
Volume Flow Rate ◽  
Operating Conditions ◽  
Design Parameters ◽  
Centrifugal Impeller ◽  
Fan Performance ◽  
Optimization Study ◽  
Leonhard Euler ◽  
The Impact

Abstract The working machines such as fans, blowers and pumps are often used for transporting fluids in technical systems. The rotating impeller is used for energy conversion of mechanical work into hydraulic work. Leonhard Euler published this relation of energy conversion in 1752–1756 and is still used today for the basic design of turbomachinery. In the present work, the Euler-Equation is described and presented in detail. Furthermore, a simplified parameterized blade channel of a centrifugal impeller is investigated with numerical simulation methods. The theoretical Euler-Equation is compared and validated with the numerical CFD-results. Based on an extensive CFD-optimization study, the impact of the impeller design parameters on the fan performance has been investigated. For this purpose, the blade shape and the operating conditions (speed and volume flow rate) were systematically varied. After an extensive grid study, the influence of the blade channel contour on the fan performance was investigated. The results of the study are presented in detail.

Development of Friction Drive Transmission

2005 ◽  
Vol 127 (4) ◽  
pp. 857-864 ◽  
Author(s):  
Xiaolan Ai ◽  
Matthew Wilmer ◽  
David Lawrentz
Keyword(s):  
Friction Coefficient ◽  
Performance Optimization ◽  
Operating Conditions ◽  
Elastic Support ◽  
Outer Ring ◽  
Design Parameters ◽  
Fe Model ◽  
Frictional Contacts ◽  
Actual Operating ◽  
Wide Range

A cylindrical friction drive was developed for electric oil pump applications. It was comprised of an outer ring, a sun roller, a loading planet, two supporting planets, and a stationary carrier. The sun roller was set eccentric to the outer ring to generate a wedge gap that facilitates a torque actuated loading mechanism for the friction drive. The loading planet was properly assembled in the wedge gap and elastically supported to the carrier. By altering the stiffness ratio of the elastic support to contact, the actual operating friction coefficient of the friction drive can be changed regardless of the wedge angle to suit for performance requirement. This provided a greater freedom for design and performance optimization. Design analysis was presented and a FE model was developed to quantify design parameters. Prototypes of the friction drive were fabricated and extensive testing was conducted to evaluate its performance. Results indicated the performance of the friction drive far exceeded the design specifications in speed, torque, and power ratings. The friction drive offered a consistent smooth and quiet performance over a wide range of operating conditions. It was capable of operating at an elevated speed of up to 12 000 rpm with adequate thermal characteristics. The friction drive demonstrated a peak efficiency above 97%. Results confirmed that the stiffness of the elastic support has an important impact on performance. The elastic support stiffness, in conjunction with the contact stiffness, determines the actual operating friction coefficient at the frictional contacts.

scholarly journals A Rotating Laser-Doppler Anemometry System for Unsteady Relative Flow Measurements in Model Centrifugal Impellers

1993 ◽  
Author(s):  
M. Abramian ◽  
J. H. G. Howard
Keyword(s):  
Laser Doppler Anemometry ◽  
Fluid Dynamic ◽  
Rotating Stall ◽  
Secondary Flows ◽  
Operating Conditions ◽  
Laser Doppler ◽  
Low Flow ◽  
Centrifugal Impeller ◽  
Flow Measurements ◽  
Relative Flow

The behaviour of the relative flow in centrifugal turbomachines is extremely complex due to the existence of various fluid dynamic phenomena and their interaction. At design and off-design operating conditions, the relative flow is subject to stationary unsteadiness which includes the flow separation and wakes associated with passage pressure gradients, secondary flows, and boundary layer stability. It is also subject to periodic unsteadiness from the rotating stall and the cyclic flow phenomena induced by the casing. This paper describes the mechanical and optical design of a rotating laser-Doppler anemometry system which allows direct measurement of the relative flow by means of an optical de-rotator. By isolating the impeller rotational frequency from the sampling frequency, it allows direct time-average measurements of the stationary behaviour of the relative flow along with the ensemble (phase)-average measurements of its periodic behaviour. Its success is demonstrated with measurements conducted in a low specific speed centrifugal impeller fitted with a single volute. Sample results of the time-averaged blade-to-blade variation of total relative velocities along with their associated turbulence intensities are reported. The (periodic) cyclic variations of the impeller exit flow, induced by the volute at low flow rates, are also presented for the suction and pressure sides.

CARBON CAPTURE AND STORAGE ENERGY CONSUMPTION AND PERFORMANCE OPTIMIZATION USING METAMODELS AND RESPONSE SURFACE METHODOLOGY

2021 ◽  
pp. 1-28
Author(s):  
Ali Allahyarzadeh-Bidgoli ◽  
Nayereh Hamidishad ◽  
Jurandir Itizo Yanagihara
Keyword(s):  
Power Consumption ◽  
Co2 Emissions ◽  
Performance Optimization ◽  
Operating Conditions ◽  
Design Parameters ◽  
Separation Performance ◽  
Co2 Removal ◽  
Operating Pressure ◽  
Heating And Cooling ◽  
And Storage

Abstract Oil and gas industries have high carbon dioxide (CO2) emissions, which is a great environmental concern. Monoethanolamine (MEA) is widely used as a solvent in CO2 capture and storage (CCS) systems. The challenge is that MEA–CCS itself is an energy-intensive process that requires optimum configuration and operation, and numerous design parameters and heat demands must be considered. Thus, the current work evaluates the energy distributions and CO2 removal efficiency of a CCS installed in floating production storage and offloading units under different operating conditions of a power- and heat-generation hub. The optimization procedures are implemented using highly accurate surrogate models for the following responses: 1) overall power consumption of CCS, 2) CCS separation performance, and 3) CCS heating and cooling demands. The input variables considered in the present research include the following: 1) the exhaust gas compositions and mass flow rate, 2) the operating pressure and temperature parameters of CCS and the injection compression unit, 3) the structural parameters of absorber and stripper columns, and 4) MEA solution parameters. The optimum CCS configuration significantly reduces the total heating and cooling demands by 62.77% (7 × 106 kW) and the overall power consumption by 8.65 % (1.8 MW), and it increases the CCS separation performance by 4.46% (97.46%) and mitigates the CO2 emissions of proper CCS by 1.02 t/h compared with conventional operating conditions.

A Rotating Laser-Doppler Anemometry System for Unsteady Relative Flow Measurements in Model Centrifugal Impellers

1994 ◽  
Vol 116 (2) ◽  
pp. 260-268 ◽  
Author(s):  
M. Abramian ◽  
J. H. G. Howard
Keyword(s):  
Laser Doppler Anemometry ◽  
Fluid Dynamic ◽  
Rotating Stall ◽  
Secondary Flows ◽  
Operating Conditions ◽  
Laser Doppler ◽  
Low Flow ◽  
Centrifugal Impeller ◽  
Flow Measurements ◽  
Relative Flow

The behavior of the relative flow in centrifugal turbomachines is extremely complex due to the existence of various fluid dynamic phenomena and their interaction. At design and off-design operating conditions, the relative flow is subject to stationary unsteadiness, which includes the flow separation and wakes associated with passage pressure gradients, secondary flows, and boundary layer stability. It is also subject to periodic unsteadiness from the rotating stall and the cyclic flow phenomena induced by the casing. This paper describes the mechanical and optical design of a rotating laser-Doppler anemometry system, which allows direct measurement of the relative flow by means of an optical derotator. By isolating the impeller rotational frequency from the sampling frequency, it allows direct time-averaged measurements of the stationary behavior of the relative flow along with the ensemble (phase)-averaged measurements of its periodic behavior. Its success is demonstrated with measurements conducted in a low specific speed centrifugal impeller fitted with a single volute. Sample results of the time-averaged blade-to-blade variation of total relative velocities along with their associated turbulence intensities are reported. The (periodic) cyclic variations of the impeller exit flow, induced by the volute at low flow rates, are also presented for the suction and pressure sides.

Multidimensional Numerical Simulations of Reacting Flow in a Non-Premixed Rotating Detonation Engine

2019 ◽  
Author(s):  
Pinaki Pal ◽  
Gaurav Kumar ◽  
Scott A. Drennan ◽  
Brent A. Rankin ◽  
Sibendu Som
Keyword(s):  
Detonation Wave ◽  
Performance Optimization ◽  
Design Space Exploration ◽  
Operating Conditions ◽  
Air Injection ◽  
Design Parameters ◽  
Cfd Model ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation

Abstract Over the last two decades, detonation based propulsion has received a great deal of attention as a potential means to achieve significant improvement in the performance of air-breathing and rocket engines. Detonative combustion mode is particularly interesting due to the resulting pressure gain from reactants to products, faster heat release, decreased entropy generation, more available work and higher thrust compared to conventional deflagrative combustion. Rotating detonation engine (RDE) is one such novel combustor concept. Realistic RDE configurations utilize separate fuel and air injection schemes, hence are not perfectly premixed. Moreover, RDE performance is governed by a large number of design parameters and operating conditions. In this context, computational fluid dynamics (CFD) has the potential to enhance the understanding of RDE combustion and aid future development/optimization of this technology. In the present work, a CFD model was developed to simulate a representative non-premixed RDE combustor. Unsteady Reynolds-Averaged Navier-Stokes (RANS) simulations were performed for the full combustor geometry (including the separate fuel and air injection ports), with hydrogen as fuel and air as the oxidizer. Adaptive mesh refinement (AMR) was incorporated to achieve a trade-off between model accuracy and computational expense. A finite-rate chemistry model along with a 10-species detailed kinetic mechanism was employed to describe the H2-Air combustion chemistry. Two operating conditions were simulated, corresponding to the same global equivalence ratio of unity but different fuel and air mass flow rates. For both conditions, the capability of the model to capture the essential detonation wave dynamics was assessed. A validation study was performed against experimental data available on detonation wave frequency/height, reactant fill height, oblique shock angle, axial pressure distribution in the channel, and fuel/air plenum pressure. The CFD model predicted the sensitivity of these wave characteristics to the operating conditions with good accuracy, both qualitatively and quantitatively. The present CFD model offers a potential capability to perform rapid design space exploration and/or performance optimization studies for realistic full-scale RDE configurations.

scholarly journals Numerical Simulation on Supercritical CO2 Fluid Dynamics in a Hollow Fiber Membrane Contactor

Computation ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 8 ◽  
Author(s):  
Hugo Valdés ◽  
Kevin Unda ◽  
Aldo Saavedra
Keyword(s):  
Hollow Fiber ◽  
Supercritical Co2 ◽  
Fiber Length ◽  
Hollow Fiber Membrane ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Membrane Contactor ◽  
Fiber Membrane ◽  
Supercritical Co2 Fluid ◽  
Membrane Contactors

This research answers the following question: What is the fluid dynamic behavior of a supercritical fluid (SCF) inside a membrane module? At this time, there is very little or no reported information that can provide an answer to this question. The research studies related to the themes of supercritical CO2 (SC-CO2), hollow fiber membrane contactors (HFMCs), and numerical simulations have mainly reported on 2D simulations, but in this work, 3D profiles are presented. Simulations were performed based on the experimental results and other simulations, using the geometry of a commercial module. The results were mainly based on the different operating conditions and geometric dimensions. A mesh study was performed to ensure the mesh non-dependence of the results presented here. It was observed that the velocity profile developed at 10 mm from the wall of the supercritical CO2 entrance pipe. A profile equilibrium around the fiber close to the entrance of the module was achieved in the experimental hollow fiber membrane contactor when compared to the case of the commercial hollow fiber membrane contactor. The results of this research provided a visualization of the boundary layer, which did not cover the entire fiber length. Finally, the results of this paper are interesting for technical applications and contribute to our understanding of the hydrodynamics of SCFs.

Fluid-Dynamic Analysis and Optimization of the Quenching Process for Hardening of Change-Speed Gears Using DOE–ANOVA Method

2004 ◽  
Vol 126 (3) ◽  
pp. 365-375 ◽  
Author(s):  
Paolo M. Congedo ◽  
Antonio Ficarella ◽  
Domenico Laforgia
Keyword(s):  
Fluid Dynamic ◽  
Operating Conditions ◽  
Design Parameters ◽  
Cooling Process ◽  
Dynamic Calculation ◽  
Hardening Process ◽  
Performance Indexes ◽  
Quenching Process ◽  
Geometry Configuration

This investigation deals with the fluid-dynamic behavior of the hardening process for change-speed gears, where a Nitrogen high pressure flow is used for quenching. At the end of the process, the gears showed a high planarity error due to a slow and non-homogeneous cooling process. A detailed fluid-dynamic calculation was performed to identify some possible technical improvements, such as varying some design parameters including the geometry configuration of the quenching chamber and the operating conditions. Three performance indexes have been defined to synthesize the quality of the hardening process and their trends have been evaluated as a function of the design and operative configuration by a DOE–ANOVA statistical analysis to obtain the best configuration.

Multipoint Design Optimization of a Transonic Compressor Blade by Using an Adjoint Method

2013 ◽  
Vol 136 (5) ◽  
Author(s):  
Jiaqi Luo ◽  
Chao Zhou ◽  
Feng Liu
Keyword(s):  
Design Optimization ◽  
Adjoint Method ◽  
Pressure Ratio ◽  
Single Point ◽  
Optimization Method ◽  
Computational Effort ◽  
Operating Conditions ◽  
Design Parameters ◽  
Transonic Compressor ◽  
Wide Range

This paper presents the application of a viscous adjoint method to the multipoint design optimization of a rotor blade through blade profiling. The adjoint method requires about twice the computational effort of the flow solution to obtain the complete gradient information at each operating condition, regardless of the number of design parameters. NASA Rotor 67 is redesigned through blade profiling. A single point design optimization is first performed to verify the effectiveness and feasibility of the optimization method. Then in order to improve the performance for a wide range of operating conditions, the blade is redesigned at three operating conditions: near peak efficiency, near stall, and near choke. Entropy production through the blade row combined with the constraints of mass flow rate and total pressure ratio is used as the objective function. The design results are presented in detail and the effects of blade profiling on performance improvement and shock/tip-leakage interaction are examined.

Sign in / Sign up

Export Citation Format

Share Document