scholarly journals Vibration analysis of ship propulsion shafting bearings

2021 ◽  
Vol 233 ◽  
pp. 01007
Author(s):  
Chen Shuo ◽  
Zhang Heng
Keyword(s):  
Steady State ◽  
Propulsion System ◽  
Operating Conditions ◽  
Modeling And Analysis ◽  
Oil Film ◽  
Ship Propulsion ◽  
Theoretical Support ◽  
Bearing Load ◽  
Practical Engineering ◽  
Bearing Structure

The ship power propulsion system is the "heart" of the ship, and the ship propulsion shafting is the core unit of the ship power propulsion system, and it is an indispensable part of the ship's propulsion torque and thrust transmission. The operating status of the propulsion shafting directly affects the operating conditions of the ship, and even the life of the ship. Bearing load is one of the most important manifestations of the operating state of the propulsion shafting. Focusing on changes in the bearing load can better study the operating state of the propulsion shafting. The research on the steady-state load of ship propulsion shafting meets the needs of ship development and has great value for practical engineering applications. This paper takes the ship propulsion shafting-oil film-bearing structure system as the research object. Through the steady-state load mathematical model of ship propulsion shafting bearings, it reveals the coupling relationship among ship propulsion shafting bearing load, oil film force, and journal position, and establishes the ship The steady-state load calculation method of the propulsion shafting bearings solves the basic theoretical problems of modeling and analysis of the steady-state operating state of the ship's propulsion shafting, and provides theoretical support for the safety prediction, management and evaluation of the ship's propulsion shafting operation.

Steady State Performance Characteristics of a Tilting Pad Thrust Bearing

2000 ◽  
Vol 123 (3) ◽  
pp. 608-615 ◽  
Author(s):  
Sergei B. Glavatskikh
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Thrust Bearing ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Shaft Speed ◽  
Oil Film ◽  
Tilting Pad ◽  
Bearing Load ◽  
Steady State Performance

The paper reports results of the experimental investigation into the steady state performance characteristics of a tilting pad thrust bearing typical of design in general use. Simultaneous measurements are taken of the pad and collar temperatures, the pressure distributions, oil film thickness, and power loss as a function of shaft speed, bearing load, and supplied oil temperature. The effect of operating conditions on bearing performance is discussed. A small radial temperature variation is observed in the collar. A reduction in minimum oil film thickness with load is approximately proportional to p−0.6, where p is an average bearing pressure. It has also been found that the oil film pressure profiles change not only due to the average bearing load but also with an increase in shaft speed and temperature of the supplied oil.

Elastic Connecting-Rod Bearing With Piezoviscous Lubricant: Analysis of the Steady-State Characteristics

1979 ◽  
Vol 101 (2) ◽  
pp. 190-197 ◽  
Author(s):  
B. Fantino ◽  
J. Frene ◽  
J. Du Parquet
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Plane Elasticity ◽  
Operating Conditions ◽  
Maximum Pressure ◽  
Connecting Rod ◽  
Oil Film ◽  
Lubricant Analysis ◽  
Relative Eccentricity ◽  
Dimensional Equation

The effect of the deformation of an automotive connecting-rod on the oil film characteristics are studied. The simultaneous elastic deformation and pressure distribution are obtained by iterative methods in steady-state conditions under realistic speeds and loads (5500 rpm, 25,000 N). Plane elasticity relations are used in this study. The following parameters are investigated: —bearing characteristics: bearing thickness B and bearing clearance C, —operating conditions: journal speed N and applied load W, —lubricant: viscosity μ0 and piezoviscous coefficient α. As a result of the deformation, the maximum pressure and the attitude angle are decreased and the relative eccentricity is greatly increased. The minimum oil film thickness is slightly but systematically decreased. The piezoviscosity effect is noticeable only at high loads: it increases slightly the oil film thickness and the maximum pressure. An empirical dimensional equation for the minimum oil film thickness hm is derived numerically for the bearing considered. Thus: hm∼μ0NW0.5(1+0.06108α)B0.12C0.09

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

Steady-state Security Assessment Based on K-Means Clustering Algorithm and Phasor Measurement Units

2020 ◽  
Vol 13 (4) ◽  
pp. 559-570
Author(s):  
Bassam A. Hemade ◽  
Hamed A. Ibrahim ◽  
Hossam E.A. Talaat
Keyword(s):  
Steady State ◽  
Clustering Algorithm ◽  
System Security ◽  
Phasor Measurement Units ◽  
Operating Conditions ◽  
Security Assessment ◽  
State Security ◽  
Phasor Measurement ◽  
Measurement Units ◽  
Silhouette Analysis

Background: The security assessment plays a crucial role in the operation of the modern interconnected power system network. Methods: Hence, this paper addresses the application of k-means clustering algorithm equipped with Principal Component Analysis (PCA) and silhouette analysis for the classification of system security states. The proposed technique works on three principal axes; the first stage involves contingency quantification based on developed insecurity indices, the second stage includes dataset preparation to enhance the overall performance of the proposed method using PCA and silhouette analysis, and finally the application of the clustering algorithm over data. Results: The proposed composite insecurity index uses available synchronized measurements from Phasor Measurement Units (PMUs) to assess the development of cascading outages. Considering different operational scenarios and multiple levels of contingencies (up to N-3), Fast Decoupled Power Flow (FDPF) have been used for contingency replications. The developed technique applied to IEEE 14-bus and 57-bus standard test system for steady-state security evaluation. Conclusion: The obtained results ensure the robustness and effectiveness of the established procedure in the assessment of the system security irrespective of the network size or operating conditions.

Mathematical modelling of salt purification by recrystallization. Countercurrent arrangement

1986 ◽  
Vol 51 (11) ◽  
pp. 2481-2488
Author(s):  
Benitto Mayrhofer ◽  
Jana Mayrhoferová ◽  
Lubomír Neužil ◽  
Jaroslav Nývlt
Keyword(s):  
Steady State ◽  
Simple Model ◽  
Mathematical Modelling ◽  
Distribution Coefficient ◽  
Mother Liquor ◽  
Equilibrium Temperature ◽  
Operating Conditions ◽  
Limiting Case

The paper presents a simple model of recrystallization with countercurrent flows of the solution and the crystals being purified. The model assumes steady-state operating conditions, an equilibrium between the outlet streams of each stage, and the same equilibrium temperature and distribution coefficient for all stages. With these assumptions, the model provides the basis for analyzing the variation in the degree of purity as a function of the number of recrystallization stages. The analysis is facilitated by the use of a diagram constructed for the limiting case of perfect removal of the mother liquor from the crystals between the stages.

scholarly journals Real-time Simulation of Ship Propulsion System

2004 ◽  
Vol 39 (12) ◽  
pp. 913-921
Author(s):  
Xianfu Hu ◽  
Hideaki Sugita ◽  
Takeshi Nakazawa ◽  
Yihuai Hu ◽  
Kengo Tanaka
Keyword(s):  
Real Time ◽  
Propulsion System ◽  
Real Time Simulation ◽  
Ship Propulsion ◽  
Time Simulation

Recent Advances in Lower Bound Shakedown Analysis

2009 ◽  
Author(s):  
Dieter Weichert ◽  
Abdelkader Hachemi
Keyword(s):  
Finite Element ◽  
Lower Bound ◽  
Process Engineering ◽  
Operating Conditions ◽  
Structural Elements ◽  
Shakedown Analysis ◽  
Material Models ◽  
Practical Engineering ◽  
Safe Operating ◽  
New Algorithms

The special interest in lower bound shakedown analysis is that it provides, at least in principle, safe operating conditions for sensitive structures or structural elements under fluctuating thermo-mechanical loading as to be found in power- and process engineering. In this paper achievements obtained over the last years to introduce more sophisticated material models into the framework of shakedown analysis are developed. Also new algorithms will be presented that allow using the addressed numerical methods as post-processor for commercial finite element codes. Examples from practical engineering will illustrate the potential of the methodology.

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