scholarly journals Suggested Mathematical Model for Specialized Subcontractor Prequalification Scrutiny and Ultimately the Performance Prediction

2014 ◽  
Vol 11 (3) ◽  
pp. 43-51
Author(s):  
Mr. Mangesh M. Kapote ◽  
◽  
Prof. Dr. S. S. Pimplikar
Keyword(s):  
Mathematical Model ◽  
Performance Prediction

Effect of Freestream Radial Velocity Component on Hydrodynamic Analysis of Propellers

1983 ◽  
Vol 27 (02) ◽  
pp. 131-134
Author(s):  
Terry Brockett
Keyword(s):  
Mathematical Model ◽  
Radial Velocity ◽  
Performance Prediction ◽  
Velocity Component ◽  
Additional Term ◽  
Radial Component ◽  
Radial Velocity Component ◽  
Hydrodynamic Analysis ◽  
The Mathematical Model ◽  
Wake Fields

For wake fields with circumferential averages that include a small radial component, an additional termarises in the mathematical model used for design or performance prediction of propellers that has been previously overlooked. This term arises from the boundary condition that the blade is impenetrable and is a function of only geometry and the inflow radial velocity component. This simple additional term is shown to be important for the example considered, leading to a variable change in camber and a pitch reduction.

Development of a Mathematical Model for Performance Prediction of Planing Catamaran in Calm Water

2019 ◽  
Vol 161 (A2) ◽  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Performance Prediction ◽  
Data Evaluation ◽  
Empirical Equations ◽  
Calm Water ◽  
Semi Empirical ◽  
The Mathematical Model ◽  
Comparison With Experimental Data

In this paper, an attempt has been made to predict the performance of a planing catamaran using a mathematical model. Catamarans subjected to a common hydrodynamic lift, have an extra lift between the two asymmetric half bodies. In order to develop a mathematical model for performance prediction of planing catamarans, existing formulas for hydrodynamic lift calculation must be modified. Existing empirical and semi-empirical equations in the literature have been implemented and compared against available experimental data. Evaluation of lift in comparison with experimental data has been documented. Parameters influencing the interaction between demi-hulls and separation effects have been analyzed. The mathematical model for planing catamarans has been developed based on Savitsky’s method and results have been compared against experimental data. Finally, the effects of variation in hull geometry such as deadrise angle and distance between two half bodies on equilibrium trim angle, resistance and wetted surface have been examined.

Outer Characteristic Experiment and Simulation of an Adjustable Damping Shock Absorber

2013 ◽  
Vol 373-375 ◽  
pp. 28-33
Author(s):  
Shi Sheng Li ◽  
Wen Kui Lan
Keyword(s):  
Mathematical Model ◽  
Flow Rate ◽  
Performance Prediction ◽  
Shock Absorber ◽  
Technical Support ◽  
Test Results ◽  
Uniform Load ◽  
Detailed Model ◽  
Pipe Line ◽  
And Performance

In this study, an adjustable damping shock absorber (ADSA) for semi-active suspension was developed. Based on the theory of hydraulics and elasticity, the ways of calculating the embranchment flow rate on the series-parallel complex pipe line (SPCPL) were deduced and employed, and the detailed mathematical model of the ADSA was established by using the equation for annular laminar deformation under a uniform load. The MATLAB software was used to simulate the detailed model, and the calculated results agree well with the test results, and the results obtained provide technical support to the design and performance prediction of the ADSA to a certain degree.

Development of a 2D+T theory for performance prediction of double-stepped planing hulls in calm water

2018 ◽  
Vol 233 (3) ◽  
pp. 886-904 ◽  
Author(s):  
Rasul Niazmand Bilandi ◽  
Abbas Dashtimanesh ◽  
Sasan Tavakoli
Keyword(s):  
Mathematical Model ◽  
Performance Prediction ◽  
Empirical Models ◽  
Two Dimensional ◽  
Reasonable Accuracy ◽  
Future Studies ◽  
Normal Forces ◽  
Calm Water ◽  
The Mean ◽  
The Mathematical Model

In this article, a mathematical model based on the 2D+T theory has been developed to predict the performance of two-stepped planing hulls in calm water. It has been attempted to develop a mathematical model without using regression formulas. It leads to development of a computational model with no common limitations related to empirical models which have an individual range of applicability. For this purpose, theoretical solution of water entry of a two-dimensional wedge section has been implemented to compute the pressure distribution over wedge section entering water, and then normal forces acting on the two-dimensional sections are computed. Bottom of the boat has been divided into three different planing surfaces including fore, middle and aft bodies. Computations are performed for each of these surfaces. By integrating the two-dimensional sectional normal forces over the entire wetted length of the vessel, the trim angle, wetted surface and resistance have been obtained. To evaluate the accuracy of the presented method, the obtained results are compared against experimental data and a previous empirical-based method developed by authors. The comparison suggests that the proposed method predicted dynamic trim angle, wetted surface and resistance of double stepped boats with reasonable accuracy. The mean errors in prediction of trim angle, wetted surface and resistance are, respectively, 13%, 16% and 8%. It should also be noted that although computation of running attitudes and resistance of double-stepped planing boats are targeted in this article, the mathematical model has been developed in such a way that it has the potential to model transverse and vertical motions of two-stepped planing hulls in future studies.

scholarly journals Research on Application of Regression Least Squares Support Vector Machine on Performance Prediction of Hydraulic Excavator

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Zhan-bo Chen
Keyword(s):  
Mathematical Model ◽  
Support Vector Machine ◽  
Least Squares ◽  
Performance Prediction ◽  
Prediction Accuracy ◽  
Support Vector ◽  
Hydraulic Excavator ◽  
Simulation Results ◽  
Research On Application ◽  
The Mathematical Model

In order to improve the performance prediction accuracy of hydraulic excavator, the regression least squares support vector machine is applied. First, the mathematical model of the regression least squares support vector machine is studied, and then the algorithm of the regression least squares support vector machine is designed. Finally, the performance prediction simulation of hydraulic excavator based on regression least squares support vector machine is carried out, and simulation results show that this method can predict the performance changing rules of hydraulic excavator correctly.

Improvement of Sailing Yacht Performance Prediction by Including Force-Moment Equilibrium for the Calculation of Helm Angle in a Velocity Prediction Program

1995 ◽  
Author(s):  
Peter van Oossanen
Keyword(s):  
Mathematical Model ◽  
Performance Prediction ◽  
Model Tests ◽  
Side Force ◽  
Prediction Program ◽  
Moment Equilibrium ◽  
Force Moment ◽  
Velocity Prediction ◽  
Sailing Yacht ◽  
Rudder Angle

Contemporary Velocity Prediction Programs (VPP's) consider the equilibrium of forces acting on a sailing yacht in the thrust direction and in the direction of the developed side force on canoe body and appendages. In addition, force-moment equilibrium is considered in the transverse plane of the yacht. In this way a solution is found for the three main unknowns in performance prediction, viz: boat speed, leeway angle and heel angle. The impact of helm angle on performance is herein ignored. In the velocity prediction program developed by Van Oossanen & Associates, a fourth equilibrium condition is included, viz: force-moment equilibrium in the horizontal plane for the calculation of the helm angle required for the equilibrium sailing condition. In this paper a description is given of some of the main problems that need to be solved when introducing this fourth equilibrium requirement. One of these is associated with the development of accurate mathematical expressions for the calculation of rudder side force and resistance, as influenced by heel angle and the proximity of the free surface. Model tests can be utilized for obtaining insight into the physical phenomena involved in such cases. Model tests were carried out in the context of an optimization study for the design of a yacht according to the International Level Class 40 (ILC40) Rule, under the International Measurement System (IMS). The analysis of some of the results of these tests with respect to improving the mathematical model for rudder side force and resistance, is described in the paper. The effect of including this mathematical model in a VPP is demonstrated in the paper by providing the results of calculations which reveal that a variation in rudder angle causes significant speed differences. It is shown that the IMS VPP that is used to calculate the rating and speed potential of ILC40 and other IMS Class yachts, in not taking into account the significant variations in performance associated with different values of the equilibrium rudder angle (and the associated rudder side force and resistance), is not sufficiently accurate.

Improved Model of Middle Layer Used for Design of Piezoelectric Bimorph Actuator

2014 ◽  
Vol 1004-1005 ◽  
pp. 393-398
Author(s):  
Yu Hua Zhou ◽  
Chang Sheng Zhou ◽  
Xiong Chen
Keyword(s):  
Mathematical Model ◽  
Composite Material ◽  
Physical Model ◽  
Performance Prediction ◽  
Adhesive Layer ◽  
Middle Layer ◽  
Electrical Load ◽  
Piezoelectric Bimorph ◽  
Actual Structure ◽  
Improved Model

In this study, the disadvantage that adhesive layer of piezoelectric bimorph actuator was ignored when model of actuator was developed by predecessors is indicated, according to the actual structure of actuator. Based on the thickness of adhesive layer and substrate, the improved model of adhesive layer that substrate and adhesive layer are combined as one layer called mid layer is proposed. Mathematical model of mid layer can be obtained with theory of composite material, which is then used to develop the model of actuator under electrical load. Another model of actuator is developed as a reference in the same way except with model of adhesive layer used by predecessors, and experiment is also presented later. Performance predicted by these two models of actuator and result measured in the experiment are compared, which comes to a conclusion that model of actuator developed with the improved model of adhesive layer conform to the physical model and is more precise in performance prediction.

scholarly journals Off-Design Performance Prediction of Turbofans Using Gasdynamics

1991 ◽  
Author(s):  
F. S. Mirza-Baig ◽  
H. I. H. Saravanamuttoo
Keyword(s):  
Mathematical Model ◽  
Performance Prediction ◽  
Dynamic Properties ◽  
Design Point ◽  
Design Performance ◽  
Gas Dynamic ◽  
Overall Performance

This paper describes a mathematical model by which the off-design performance of turbofans can be predicted, knowing just the design point parameters. Off-design performance has been estimated by using gas-dynamic properties of the exhaust nozzles, which regulate the aerothermodynamic behaviour of the upstream components. Approximate overall performance of a turbofan at typical cruising conditions can be estimated, making the use of compressor and turbine maps redundant.

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