Transient Hydroelastic Analysis of Pump Performance of an SES-Waterjet System

2012 ◽  
Author(s):  
Michael R. Motley ◽  
Yin L. Young ◽  
Brant R. Savander
Keyword(s):  
Surface Effect ◽  
Dynamic Performance ◽  
Operating Conditions ◽  
Geometric Constraints ◽  
Propulsion Systems ◽  
Structural Dynamic ◽  
Surface Vessels ◽  
Hydroelastic Analysis ◽  
Cargo Capacity ◽  
High Thrust

Surface Effect Ships (SES) have great potential to increase the speed and cargo capacity of modern surface vessels. Waterjets are typically used for propulsion of SES because of the geometric constraints and its ability to absorb high thrust and power requirements. The objective of this paper is to investigate the transient hydroelastic performance of waterjet propulsion systems. The goal is to advance the fundamental understanding of the transient hydrodynamic and structural dynamic performance of waterjet propulsion systems with consideration for non-uniform inflow and transient fluid cavitation at heavily loaded operating conditions. Special attention is given to investigating the effects of flow non-uniformity and fluid cavitation on the system performance, as well as the structural dynamic performance of the rotor and stator blades.

Power Test System Development and Dynamic Performance State Estimation Based on Hub Motor Vehicle

2020 ◽  
Vol 13 (2) ◽  
pp. 126-140
Author(s):  
Jing Gan ◽  
Xiaobin Fan ◽  
Zeng Song ◽  
Mingyue Zhang ◽  
Bin Zhao
Keyword(s):  
Real Time ◽  
Dynamic Performance ◽  
Test System ◽  
Operating Conditions ◽  
Motor Vehicles ◽  
Maximum Speed ◽  
Performance Parameters ◽  
Power Performance ◽  
Power Test ◽  
The Real

Background: The power performance of an electric vehicle is the basic parameter. Traditional test equipment, such as the expensive chassis dynamometer, not only increases the cost of testing but also makes it impossible to measure all the performance parameters of an electric vehicle. Objective: A set of convenient, efficient and sensitive power measurement system for electric vehicles is developed to obtain the real-time power changes of hub-motor vehicles under various operating conditions, and the dynamic performance parameters of hub-motor vehicles are obtained through the system. Methods: Firstly, a set of on-board power test system is developed by using virtual instrument (Lab- VIEW). This test system can obtain the power changes of hub-motor vehicles under various operating conditions in real-time and save data in real-time. Then, the driving resistance of hub-motor vehicles is analyzed, and the power performance of hub-motor vehicles is studied in depth. The power testing system is proposed to test the input power of both ends of the driving motor, and the chassis dynamometer is combined to test so that the output efficiency of the driving motor can be easily obtained without disassembly. Finally, this method is used to carry out the road test and obtain the vehicle dynamic performance parameters. Results: The real-time current, voltage and power, maximum power, acceleration time and maximum speed of the vehicle can be obtained accurately by using the power test system in the real road experiment. Conclusion: The maximum power required by the two motors reaches about 9KW, and it takes about 20 seconds to reach the maximum speed. The total power required to maintain the maximum speed is about 7.8kw, and the maximum speed is 62km/h. In this article, various patents have been discussed.

Experimental and Analytical Investigations of a Low Pressure Model Turbine During Forced Response Excitation

2010 ◽  
Author(s):  
Christoph Heinz ◽  
Markus Schatz ◽  
Michael V. Casey ◽  
Heinrich Stu¨er
Keyword(s):  
Degrees Of Freedom ◽  
Timing Analysis ◽  
Dynamic Performance ◽  
Amplitude Distribution ◽  
Low Pressure ◽  
Forced Response ◽  
Operating Conditions ◽  
Linear Regression Method ◽  
Rotor Shaft ◽  
Aerodynamic Damping

To guarantee a faultless operation of a turbine it is necessary to know the dynamic performance of the machine especially during start-up and shut-down. In this paper the vibration behaviour of a low pressure model steam turbine which has been intentionally mistuned is investigated at the resonance point of an eigenfrequency crossing an engine order. Strain gauge measurements as well as tip timing analysis have been used, whereby a very good agreement is found between the methods. To enhance the interpretation of the data measured, an analytical mass-spring-model, which incorporates degrees of freedom for the blades as well as for the rotor shaft, is presented. The vibration amplitude varies strongly from blade to blade. This is caused by the mistuning parameters and the coupling through the rotor shaft. This circumferential blade amplitude distribution is investigated at different operating conditions. The results show an increasing aerodynamic coupling with increasing fluid density, which becomes visible in a changing circumferential blade amplitude distribution. Furthermore the blade amplitudes rise non-linearly with increasing flow velocity, while the amplitude distribution is almost independent. Additionally, the mechanical and aerodynamic damping parameters are calculated by means of a non-linear regression method. Based on measurements at different density conditions, it is possible to extrapolate the damping parameters down to vacuum conditions, where aerodynamic damping is absent. Hence the material damping parameter can be determined.

Double Scroll Turbine for Automotive Applications: Engine Operating Point Versus Dynamic Blade Stress From Forced Response Vibration

2018 ◽  
Author(s):  
David Hemberger ◽  
Roberto De Santis ◽  
Dietmar Filsinger
Keyword(s):  
Pulse Energy ◽  
Internal Combustion Engines ◽  
Forced Response ◽  
Operating Conditions ◽  
Blade Vibration ◽  
Structural Dynamic ◽  
Vibration Excitation ◽  
Engine Combustion ◽  
Operating Points ◽  
Combustion Cycle

As a means of meeting ever increasing emissions and fuel economy demands car manufacturers are using aggressive engine downsizing. To maintain the power output of the engine turbocharging is typically used. Compared to Mono scroll turbines, with a multi-entry system the individual volute sizing can be better matched to the single mass flow pulse from the engine cylinders. The exhaust pulse energy can be better utilised by the turbocharger turbine improving turbocharger response. Additionally the interaction of the engine exhaust pulses can be better avoided, improving the scavenging of the engine. Besides the thermodynamic advantages, the multi-entry turbine represents a challenge to the structural dynamic design of the turbine. A higher number of turbine wheel resonance points can be expected during operation. In addition, the increased use of exhaust pulse energy leads to a distinct accentuation of the blade vibration excitation. Using validated engine models, the interaction of the multi-entry turbine with the engine has been analyzed and various operating points, which may be critical for the blade vibration excitation, have been classified. These operating points deliver the input variables for unsteady computational flow dynamics (CFD) analyses. From these calculations unsteady blade forces were derived providing the necessary boundary conditions for the structural dynamic analyses by spatially and temporally high-resolved absolute pressures on the turbine surface. Goal of the investigation is to identify critical operating conditions. Important is also to investigate the effect of a scroll connection valve on blade excitation. The investigations utilize validated tools that were introduced and successfully applied to several turbine types in a series of publications over recent years. It can be stated that the engine operating condition and the admission type significantly influence the forced response reaction of the blade to the different excitation orders (EO). In case of equal admission even (or multiples of two) EOs generate the largest dynamic blade stress as can be expected due to the two turbine inlet segments. This reaction also increases with the engine speed. In the case of unequal admission, the odd EOs produce the largest forced response reaction. The maximum dynamic blade stress occurs in the region where the scroll connection is just closed. Above all, the scroll connection valve influences the Beta value and thus the basic behavior — unequal or equal admission. It has been possible to reconstruct the forced response behavior of the turbine blade within an engine combustion cycle. For the first time it could be shown for a double scroll application that there is a significant dynamic blade stress change dependent on the engine crankshaft angle. Certainly, due to the inertia of the mass and damping (mass, structure, flow), the blade will not exactly follow the predicted course. However, it is clear that the transient processes within an engine combustion cycle will affect the dynamic blade stress. This applies to the turbine wheels investigated in the work at hand with low damping, high eigenfrequencies and the considered internal combustion engines — as they are typically used in the passenger car sector.

Direct Outer Ring Cooling of a High Speed Jet Engine Mainshaft Ball Bearing: Experimental Investigation Results

2010 ◽  
Author(s):  
Peter Gloeckner ◽  
Klaus Dullenkopf ◽  
Michael Flouros
Keyword(s):  
Power Dissipation ◽  
High Speed ◽  
Ball Bearing ◽  
Operating Conditions ◽  
Outer Ring ◽  
Outer Diameter ◽  
Propulsion Systems ◽  
Jet Engine ◽  
Power Loss Reduction ◽  
The Impact

Operating conditions in high speed mainshaft ball bearings applied in new aircraft propulsion systems require enhanced bearing designs and materials. Rotational speeds, loads, demands on higher thrust capability, and reliability have increased continuously over the last years. A consequence of these increasing operating conditions are increased bearing temperatures. A state of the art jet engine high speed ball bearing has been modified with an oil channel in the outer diameter of the bearing. This oil channel provides direct cooling of the outer ring. Rig testing under typical flight conditions has been performed to investigate the cooling efficiency of the outer ring oil channel. In this paper the experimental results including bearing temperature distribution, power dissipation, bearing oil pumping and the impact on oil mass and parasitic power loss reduction are presented.

scholarly journals Determining the environmental indicators for vehicles of different categories in relation to CO2 emission based on road tests

2017 ◽  
Vol 170 (3) ◽  
pp. 66-72
Author(s):  
Jerzy MERKISZ ◽  
Łukasz RYMANIAK
Keyword(s):  
Co2 Emissions ◽  
Operating Time ◽  
Environmental Indicators ◽  
Operating Conditions ◽  
Si Engine ◽  
Propulsion Systems ◽  
System A ◽  
In Series ◽  
Series Configuration ◽  
Ci Engine

The article discusses the possibility of determining the environmental indicators for vehicles of different categories in relation to CO2 emissions. These are called toxicity indicators because they concern the compounds: CO, THC and NOx. Three Euro V compliant vehicles with different propulsion systems types were used for the study: a 0.9 dm3 urban passenger car with a SI engine and a start-stop system, a 2.5 dm3 off-road vehicle with a CI engine, and a city bus with a hybrid drive system in series configuration and a CI engine with a displacement of 6.7 dm3. Measurements were made in actual operating conditions in the Poznan agglomeration using a portable emissions measurement system (PEMS). The paper presents the characteristics of the operating time shares of vehicles and propulsion systems as well as CO2 emissions depending on the engine load and crankshaft rotational speed for individual vehicles. The determined toxicity indicators allowed to indicate their usefulness, to make comparisons between tested vehicles, and to identify directions for further work on the application and interpretation of these indicators.

Flexibility of Seakeeping Simulation Tools for Landing Craft Hullforms

2017 ◽  
Author(s):  
Kevin Silva ◽  
Andrew Silver ◽  
Kenneth Weems ◽  
David Wundrow ◽  
Sheguang Zhang
Keyword(s):  
Surface Effect ◽  
Water Jet ◽  
Operating Conditions ◽  
Physical Models ◽  
Simulation Tools ◽  
Test Conditions ◽  
Seakeeping Performance ◽  
Surface Effect Ship ◽  
Analytical Tools ◽  
Large Amplitude Motion

As the operational requirements of landing craft expand to faster speeds and higher sea states, more complex hullforms are being proposed to meet these requirements. The seakeeping performance of such vessels can become difficult to predict. Analytical tools must be flexible in order to handle the variety of operating conditions, hull geometries, loading conditions, and other attributes. The analytical seakeeping models should be based on the physical models of the hydrodynamic phenomena rather than case-specific empirical tuning. This paper describes a study that evaluated the ability of the Large Amplitude Motion Program (LAMP) to simulate traditional and non-traditional landing craft hullforms in varying operating conditions. The hullforms include a traditional semi-planing monohull, a semi-planing water jet propelled “W” shaped hull, a water jet propelled catamaran, and a catamaran Surface Effect Ship (SES) style hull. The measures taken to model each hullform and test conditions in LAMP are discussed and the correlation between experimental data and LAMP predictions are presented through comparisons of motions and accelerations.

Dynamic performance of optimized microwave assisted extraction to obtain Eucalyptus essential oil: energy requirements and environmental impact

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Elizabeth Lainez-Cerón ◽  
Aurelio López-Malo ◽  
Enrique Palou ◽  
Nelly Ramírez-Corona
Keyword(s):  
Environmental Impact ◽  
Essential Oil ◽  
Dynamic Performance ◽  
Maximum Yield ◽  
Operating Conditions ◽  
Energy Requirements ◽  
Microwave Assisted Extraction ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Eucalyptus Essential Oil

Abstract The dynamic performance of a microwave-assisted extraction (MAE) was studied during the extraction of eucalyptus essential oil. The effect of different process variables such as solid/liquid ratio (1:1, 1:3, or 1:5), stirring speed (0, 200, or 400 rpm), and power microwave output (360, 450, or 540 W) on obtained yield, energy requirements and environmental impact were assessed. The maximum yield was 1.26 ± 0.01% and the steam generation velocities between 4.8 and 8.8 g/min favor the extraction. In terms of environmental impact, the lowest EI99 value obtained was 6.93 ± 0.1 mPT/g. A multi-response optimization was performed to identify the operating conditions that maximize yield, while minimize energy requirements and environmental impact. Temperature dynamics and extraction kinetics were fitted to a second-order transfer function model, aimed to evaluate the role of heating patterns on the process performance. Finally, a controlled temperature experiment was carried out under the optimal conditions.

Optimal Design of Modified Power System Stabilizer Using Multi Objective Based Bio Inspired Algorithms

2018 ◽  
Vol 7 (4) ◽  
pp. 17-55 ◽  
Author(s):  
Dasu Butti ◽  
Siva Kumar Mangipudi ◽  
Srinivasarao Rayapudi
Keyword(s):  
Power System ◽  
Dynamic Performance ◽  
Operating Conditions ◽  
Power System Stabilizer ◽  
Value Analysis ◽  
Multi Objective ◽  
De Algorithm ◽  
System Data ◽  
Bus Voltage ◽  
System Stabilizer

In this article, a multi objective and a novel objective based Power System Stabilizer (PSS) design is proposed for a modified Heffron - Philiphs model (MHP) using bio inspired algorithms. A conventional Heffron – Philphs (CHP) model is developed by taking infinite bus voltage as reference, whereas MHP model is developed by taking transformer high voltage bus voltage as reference, which makes independent of external system data for the PSS design. PSS parameters are optimized using differential evolution (DE) algorithm and Firefly (FF) algorithm to obtain better dynamic response. The proposed method is tested on various operating conditions under different typical disturbances to test efficacy and robustness. Simulation results prove that better dynamic performance is obtained with the proposed stabilizers over the fixed gain stabilizers. This method of tuning would become a better alternative to conventional stabilizers as conventional stabilizers require retuning of parameters mostly when operating condition changes, which is a time-consuming process and laborious. Eigen value analysis is also done to prove the efficacy of the proposed method over the conventional methods.

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