scholarly journals Optimization and Comparison of Two Technologies for the Manufacture of Blades for Flow path HPC Turbine K-330-23.5

2021 ◽  
pp. 5-14
Author(s):  
Oleksandr Usatyi ◽  
Olena Avdieieva ◽  
Ihor Palkov ◽  
Sergii Palkov ◽  
Oleh Ishchenko
Keyword(s):  
Comparative Analysis ◽  
Flow Path ◽  
Rotor Blades ◽  
Design Parameters ◽  
Optimal Solutions ◽  
Profile Losses ◽  
Negative Effect ◽  
Multiparameter Optimization

The article presents the results of multiparameter optimization of the structural and thermogasdynamic parameters of the flow path of the HPC K-330-23.5, obtained using the developed CAD “Turboagregat”. The found 12 optimal solutions for the flow path of the HPCK-330-23.5 make it possible not only to assess the effect of the design parameters and the number of blades of the HPC stages on the HPC efficiency, but also to carry out a comparative analysis of two technological approaches to manufacturing the rotor blades – with and without trimming the initial edges. Calculations have confirmed the negative effect of increasing the radius of the “tummy” circle on the nature of the flow and on the efficiency of the cascades. In cascades with increased profiles by 9.83 % with a radius of the “tummy” circle, the coefficient of profile losses of the cascade increased by 0.07 % (absolute) in comparison with the original cascade from the original 1MMK-U profiles.

scholarly journals A new compact hydraulic propeller turbine for low heads

2019 ◽  
Vol 116 ◽  
pp. 00005
Author(s):  
Dario Barsi ◽  
Marina Ubaldi ◽  
Pietro Zunino ◽  
Robert Fink
Keyword(s):  
3D Model ◽  
Design Procedure ◽  
Meridional Flow ◽  
Flow Path ◽  
Rotor Blades ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Statistical Correlations ◽  
Overall Performance ◽  
Working Parameters

In this paper, a design procedure for a compact hydraulic propeller turbine for low heads is proposed and developed. The design is based upon classical criteria and on the employment of statistical correlations, which relates the main geometrical parameters to the fundamental design parameters of turbomachinery. The procedure for obtaining the meridional flow path and the stator vanes and rotor blades geometries is explained step by step. The obtained 3D model is employed to carry out a CFD calculation in order to obtain the turbine overall performance and main working parameters.

Robust Design Techniques for Evaluating Fuel Cell Thermal Performance

2006 ◽  
Author(s):  
Kenneth J. Kelly ◽  
Gregory C. Pacifico ◽  
Michael Penev ◽  
Andreas Vlahinos
Keyword(s):  
Fuel Cell ◽  
Heat Generation ◽  
Thermal Performance ◽  
Gas Flow ◽  
Internal Heat ◽  
Flow Path ◽  
Coolant Flow ◽  
Design Parameters ◽  
Fuel Cell Stack ◽  
Path Design

The National Renewable Energy Laboratory (NREL) and Plug Power Inc. have been working together to develop fuel cell modeling processes to rapidly assess critical design parameters and evaluate the effects of variation on performance. This paper describes a methodology for investigating key design parameters affecting the thermal performance of a high temperature, polybenzimidazole (PBI)-based fuel cell stack. Nonuniform temperature distributions within the fuel cell stack may cause degraded performance, induce thermo-mechanical stresses, and be a source of reduced stack durability. The three-dimensional (3-D) model developed for this project includes coupled thermal/flow finite element analysis (FEA) of a multi-cell stack integrated with an electrochemical model to determine internal heat generation rates. Sensitivity and optimization algorithms were used to examine the design and derive the best choice of the design parameters. Initial results showed how classic design-of-experiment (DOE) techniques integrated with the model were used to define a response surface and perform sensitivity studies on heat generation rates, fluid flow, bipolar plate channel geometry, fluid properties, and plate thermal material properties. Probabilistic design methods were used to assess the robustness of the design in response to variations in load conditions. The thermal model was also used to develop an alternative coolant flow-path design that yields improved thermal performance. Results from this analysis were recently incorporated into the latest Plug Power coolant flow-path design. This paper presents an evaluation of the effect of variation on key design parameters such as coolant and gas flow rates and addresses uncertainty in material thermal properties.

Improving Gerotor Pump Performance Trough Design, Modeling and Simulation

2021 ◽  
Author(s):  
Lozica Ivanović ◽  
Miloš Matejić
Keyword(s):  
Low Noise ◽  
Operating Conditions ◽  
Design Parameters ◽  
Pump Efficiency ◽  
Hydraulic Systems ◽  
Wear Process ◽  
Gerotor Pump ◽  
Gerotor Pumps ◽  
Negative Effect ◽  
Compact Design

Gerotor pumps are well known by a compact design, simple structure and low noise level, which makes them suitable for use in the automotive industry, and especially in hydraulic systems for engine lubrication. One of the main disadvantages of gerotor pumps is the inability to adjust to wear, which significantly reduces the pump efficiency. In order to mitigate the negative effect of the inevitable wear process, this paper presents a methodology for determining the optimal combination of trochoid gears design parameters for a defined aspect. An appropriate mathematical model has been developed to analyze the effect of changes in gear design parameters in relation to maximum contact stresses, pressure changes in gerotor pump chambers and wear rate proportional factor (WRPF). Verification of the developed models was performed by realizing physical pairs of gears and laboratory experiments with simulation of pump operating conditions. The results and conclusions presented in this paper, with an emphasis on the actual work processes, bring very important perspectives for the gerotor pumps design with improved performance.

scholarly journals Comparative analysis, design and optimisation of a 48 channel DWDM system using various design parameters

2019 ◽  
Author(s):  
◽  
Jerrin Zachariah Mohan
Keyword(s):  
Comparative Analysis ◽  
Design Parameters ◽  
Communication Link ◽  
Q Factor ◽  
Bit Rate ◽  
Analysis Model ◽  
Transmission Impairments ◽  
Compensation Technique ◽  
Linear Effects ◽  
Dwdm System

In the current era, there is an ever-growing demand for data hungry applications and services that need large amounts of bandwidth to send digital information at very high speeds. In order to meet this challenge for higher bandwidth capacity, Dense Wave Division Multiplexing (DWDM) is used as the strategy to transmit multiple high-bit rate channels at extremely narrow channel spacings over a single fiber core. However, this gives rise to detrimental transmission impairments such as linear effects and non-linear effects. The dissertation minimises the impairments by optimally designing a new DWDM system that produces a detectable and acceptable quality of signal at the receiver. In this dissertation, a comparative analysis is performed on the simulative design of a 48-channel DWDM system that has a 25 Gb/s bit rate and a 100 km transmission distance. The research mitigates the effects of transmission impairments such that an error-free matched communication link is produced for equally spaced (ES) channels of 100 GHz, 50 GHz, 25 GHZ and 12.5 GHz and 6.25 GHz. Various design parameters are used to create the comparative analysis model to optimise the 48 channel DWDM network. The design is simulated using the Optisystem simulation platform and the signal analysis is based on the bit error rate (BER) and quality (Q) factor of the received signal’s eye diagrams. It is established in the desertion that modified networks with matched active components has ES frequency channels that are aligned to each other and has a higher optical signal to noise ratio (OSNR) than mismatched networks. The maximum signal power and OSNR of the 3-erbium doped fiber amplifier (EDFA)-post symmetric compensation technique is always higher than the 1-EDFA post compensation technique for all channel spacings in any type of network. Modified duobinary return to zero (MDRZ) when compared to non-return to zero (NRZ) and return to zero (RZ) has a greater dispersion tolerance, higher fiber non-linearity tolerance and a higher acceptable signal transmission over longer distances with the least amount of errors. The optimised design parameter configurations produce the highest signal performance (highest Q factor > 6 and lowest BER > 10-9) and the highest bandwidth efficiency for the RZ Modulation (at 100 GHz, 50 GHz and 25 GHz channel spacings) and MDRZ Modulation (at 12.5 and 6.25 GHz channel spacing).

Pressure and Suction Surfaces Redesign for High Lift Low Pressure Turbines

2001 ◽  
Author(s):  
P. González ◽  
I. Ulizar ◽  
R. Vázquez ◽  
H. P. Hodson
Keyword(s):  
Separation Bubble ◽  
Low Pressure ◽  
Axial Position ◽  
Design Parameters ◽  
Suction Surface ◽  
High Lift ◽  
Pressure Surface ◽  
Turbine Efficiency ◽  
Profile Losses ◽  
Lp Turbine

Nowadays there is a big effort toward improving the low pressure turbine efficiency even to the extent of penalising other relevant design parameters. LP turbine efficiency influences SFC more than other modules in the engine. Most of the research has been oriented to reduce profile losses, modifying the suction surface, the pressure surface or the three-dimensional regions of the flow. To date, the pressure surface has received very little attention. The dependence of the profile losses on the behaviour of both pressure and suction surfaces has been investigated for the case of a high lift design that is representative of a modern civil engine LP turbine. The experimental work described in this paper consists on two different sets of experiments: the first one concluded an improved pressure surface definition and the second set was oriented to achieve further improvement in losses modifying the profile suction surface. Three profiles were designed and tested over a range of conditions. The first profile is a thin-solid design. This profile has a large pressure side separation bubble extending from near the leading edge to mid-chord. The second profile is a hollow design with the same suction surface as the first one but avoiding pressure surface separation. The third one is also a hollow design with the same pressure surface as the second profile but more aft loaded suction surface. The study is part of a wider on-going research programme covering the effects of the different design parameters on losses. The paper describes the experiments conducted in a low-speed linear cascade facility. It gathers together steady and unsteady loss measurements by wake traverse and surface pressure distributions for all the profiles. It is shown that thick profiles generate only around 90% of the losses of a thin-solid profile with the same suction surface. The results support the idea of an optimum axial position for the peak Mach number. Caution is recommended as profile aft loading would not be a completely secure method for reducing losses.

A Performance-Based Representation for Engineering Design

1999 ◽  
Author(s):  
Liang Zhu ◽  
David Kazmer
Keyword(s):  
Engineering Design ◽  
Design Solution ◽  
Design Parameters ◽  
Feasible Region ◽  
Pareto Optimal Solutions ◽  
Optimal Solutions ◽  
Performance Orientation ◽  
Practical Design ◽  
Current Engineering ◽  
A Performance

Abstract A performance-based representation is presented, which uses the Performance Orientation Chart (POC) to aid the designer throughout an interactive design process. Assuming that all performance attributes can be expressed as functions of the design parameters, three types of graphical matrix are shown in the POC: 1) The design form depicts the performance attributes varying with the correspondent design parameters; 2) The performance dependency addresses the trade-off information among the multiple specifications based on Pareto optimal solutions; 3) The parameter constraint space defines the feasible region of the design, parameters within the, active specification limits. Guided by these graphical matrices, the designer can interactively develop the design solution to satisfy multiple specifications. The methodology was applied to a practical design problem to explicate how the POC can help the designer acquire a satisfying design solution with extensive confidence. Finally, the discussion, indicates that the performance-based representation is significantly compatible with other current engineering design methodologies.

A Scalability Study of the Multirotor Biplane Tailsitter Using Conceptual Sizing

2020 ◽  
Vol 65 (1) ◽  
pp. 1-18
Author(s):  
Ananth Sridharan ◽  
Bharath Govindarajan ◽  
Inderjit Chopra
Keyword(s):  
Power Plants ◽  
Transmission Efficiency ◽  
Rotor Blades ◽  
Transmission Model ◽  
Design Parameters ◽  
Skin Thickness ◽  
Weight Class ◽  
Rotor Design ◽  
Load Carrying ◽  
Beam Lattice

This paper presents a methodology for preliminary sizing of unconventional rotorcraft using a physics-based approach to estimate the weight of primary load-carrying members and rotor efficiencies. The methodology is demonstrated for a quadrotor biplane tailsitter, a tilt-body configuration that can operate in both helicopter and airplane mode. A beam lattice framework for the airframe structure is iteratively adjusted in the sizing loop to accommodate the limit loads. A similar semianalytical approach is followed to size and estimate weight of the rotor blades. Using this analysis, a consistent combination of vehicle macrodimensions (rotor radius, wing span) and tip speed as well as detailed design parameters (spar height, skin thickness, and cross-section weight) are obtained simultaneously. To compare the effectiveness of various power plants within a weight class, the sizing methodology was modified to identify the payload for three different vehicle takeoff weights: 20, 50, and 1000 lb. To enable operation within constrained urban canyons, the effect of restricting maximum vehicle dimensions to 10 ftfor the 1000-lb designs is also examined. An electric transmission model is used in these designs owing to its relative insensitivity of transmission efficiency to the operating RPM. A variable-pitch and variable-RPM rotor design allows for control redundancy within each rotor.

scholarly journals Comparative Analysis of Cutting Forces, Torques, and Vibration in Drilling of Bovine, Porcine, and Artificial Femur Bone with Considerations for Robot Effector Stiffness

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Oluseyi Adewale Orelaja ◽  
Xingsong Wang ◽  
Donghua Shen ◽  
Dauda Sh. Ibrahim ◽  
Tianzheng Zhao ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Cutting Forces ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Drilling Process ◽  
Robot Arm ◽  
Drilling Force ◽  
Significant Drop ◽  
Negative Effect ◽  
Conventional Drilling

Bone drilling is known as one of the most sensitive milling processes in biomedical engineering field. Fracture behavior of this cortical bone during drilling has attracted the attention of many researchers; however, there are still impending concerns such as necrosis, tool breakage, and microcracks due to high cutting forces, torques, and high vibration while drilling. This paper presents a comparative analysis of the cutting forces, torques, and vibration resulted on different bone samples (bovine, porcine, and artificial femur) using a 6dof Robot arm effector with considerations of its stiffness effects. Experiments were conducted on two spindle speeds of 1000 and 1500 rpm with a drill bit diameter of 2.5 mm and 6 mm depth of cut. The results obtained from the specimens were processed and analyzed using MATLAB R2015b and Visio 2000 software; these results were then compared with a prior test using manual and conventional drilling methods. The results obtained show that there is a significant drop in the average values of maximum drilling force for all the bone specimens when the spindle speed changes from 1000 rev/min to 1500 rev/min, with a drop from (20.07 to 12.34 N), approximately 23.85% for bovine, (11.25 to 8.14 N) with 16.03% for porcine, and (5.62 to 3.86 N) with 33.99% for artificial femur. The maximum average values of torque also decrease from 41.2 to 24.2 N·mm (bovine), 37.0 to 21.6 N·mm (porcine), and 13.6 to 6.7 N·mm (artificial femur), respectively. At an increase in the spindle speed, the vibration amplitude on all the bone samples also increases considerably. The variation in drilling force, torque, and vibration in our result also confirm that the stiffness of the robot effector joint has negative effect on the bone precision during drilling process.

A comparative analysis of embodied carbon in high-rise buildings regarding different design parameters

2017 ◽  
Vol 161 ◽  
pp. 663-675 ◽  
Author(s):  
Vincent J.L. Gan ◽  
C.M. Chan ◽  
K.T. Tse ◽  
Irene M.C. Lo ◽  
Jack C.P. Cheng
Keyword(s):  
Comparative Analysis ◽  
Design Parameters ◽  
High Rise ◽  
Embodied Carbon
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