Theory Analysis and Experimental Investigation of Liquid Droplets Evaporization in High Speed Flow

Volume 3 ◽  
2004 ◽  
Author(s):  
Kunpeng Zhang ◽  
Song Zou ◽  
Haigui Wang ◽  
Weiming Pan ◽  
Fei Xue
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
Cooling System ◽  
Liquid Droplets ◽  
Theory Analysis ◽  
Compression Process ◽  
Spray System ◽  
Speed Flow ◽  
Wet Compression ◽  
The Mathematical Model

Experimental study of spray cooling system with wet compression has been carried out on a small hot wind tunnel. A mathematical model is established for liquid droplets evaporization and a set of experiments have been carried out to study the inherent law of liquid spray with evaporization. The experiment result is accord with the theory analysis. The result of this paper will be good reference for spray system design for a wet compression system. And the detail information of the experiment and the mathematical model take us further understanding of the real wet compression process.

Experimental Investigation and Numerical Simulation of Liquid Droplet Vaporization in a Compression System With Wet Compression

2004 ◽  
Author(s):  
Kunpeng Zhang ◽  
Song Zou ◽  
Weiming Pan ◽  
Fei Xue
Keyword(s):  
Cooling System ◽  
Liquid Droplet ◽  
Spray Cooling ◽  
Liquid Droplets ◽  
Compression Process ◽  
Compression System ◽  
Droplet Vaporization ◽  
Spray System ◽  
Good Accord ◽  
Wet Compression

Experimental study of spray cooling system with wet compression has been carried out on a small hot wind tunnel. A mathematical model is established for liquid droplets evaporization and a 3D calculation bound on the model have been carried out. The results are in good accord with the experimental data. This paper will be good reference for spray system design for a wet compression system. And the detail information of the experiment and numerical computation take us further understanding of the real wet compression process.

Research on the Performance Simulation of the Transmission System of Loader with Secondary Regulating Technique

2010 ◽  
Vol 426-427 ◽  
pp. 299-302
Author(s):  
Fa Ye Zang
Keyword(s):  
Mathematical Model ◽  
Fuzzy Control ◽  
Energy Saving ◽  
High Speed ◽  
Transmission System ◽  
Performance Simulation ◽  
Constant Torque ◽  
Braking Torque ◽  
The Mathematical Model ◽  
Inertial Energy

Based on deeply analyzing the working principles and energy-saving theory of loader secondary regulating transmission system, regenerating the transmission system’s inertial energy by controlling constant torque was put forward. Considering large changes of the parameters of the transmission system and its non-linearity, a fuzzy control was adopted to control the transmission system, and the mathematical model of the system was established, then the simulations of the performance of the transmission system has been conducted. The conclusion was made that the inertial energy can be reclaimed and reused in the system by the application of the secondary regulation technology, and braking by controlling constant torque is stable, it can ensure the security of braking at high speed and also permits changing the efficiency of recovery by changing the braking torque. The system’s power has been reduced and energy saving has been achieved.

Increasing the mobility of a high-speed tracked vehicle based on a controlled skid algorithm

2020 ◽  
pp. 29-33
Author(s):  
S. V. Kondakov ◽  
O.O. Pavlovskaya ◽  
I.D. Ivanov ◽  
A.R. Ishbulatov
Keyword(s):  
Mathematical Model ◽  
Dynamic Stability ◽  
Simulation Modeling ◽  
Automatic System ◽  
High Speed ◽  
Control Algorithm ◽  
Loss Of Stability ◽  
Tracked Vehicle ◽  
Hydrostatic Transmission ◽  
The Mathematical Model

A method for controlling the curvilinear movement of a high-speed tracked vehicle in a skid without loss of stability is proposed. The mathematical model of the vehicle is refined. With the help of simulation modeling, a control algorithm is worked out when driving in a skid. The effectiveness of vehicle steering at high speed outside the skid is shown. Keywords: controlled skid, dynamic stability, steering pole displacement, hydrostatic transmission, automatic system, fuel supply. [email protected]

scholarly journals The analysis of flutter characteristics based on generalized parameters of eigen modes of vibrations

2021 ◽  
pp. 95-102
Author(s):  
K. I Barinova ◽  
A. V Dolgopolov ◽  
O. A Orlova ◽  
M. A Pronin
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
Dynamic Pressure ◽  
Mode Shapes ◽  
Scaled Model ◽  
Design Specifications ◽  
Operation Conditions ◽  
Flutter Analysis ◽  
Generalized Parameters ◽  
The Mathematical Model

Flutter numerical analysis of a dynamically scaled model (DSM) of a high aspect ratio wing was performed using experimentally obtained generalized parameters of eigen modes of vibrations. The DSM is made of polymer composite materials and is designed for aeroelastic studies in a high-speed wind tunnel. As a result of the analysis, safe operation conditions (flutter limits) of the DSM were determined. The input data to develop the flutter mathematical model are DSM modal test results, i.e. eigen frequencies, mode shapes, modal damping coefficients, and generalized masses obtained from the experiment. The known methods to determine generalized masses have experimental errors. In this work some of the most practical methods to get generalized masses are used: mechanical loading, quadrature component addition and the complex power method. Errors of the above methods were analyzed, and the most reliable methods were selected for flutter analysis. Comparison was made between the flutter analysis using generalized parameters and a pure theoretical one based on developing the mathematical model from the DSM design specifications. According to the design specifications, the mathematical model utilizes the beam-like schematization of the wing. The analysis was performed for Mach numbers from 0.2 to 0.8 and relative air densities of 0.5, 1, 1.5. Comparison of the two methods showed the difference in critical flutter dynamic pressure no more than 6%, which indicates good prospects of the flutter analysis based on generalized parameters of eigen modes.

scholarly journals Suppression of Ground Borne Vibration Induced by High-Speed Lines

2018 ◽  
Vol 152 ◽  
pp. 02001
Author(s):  
Ali Mohamed Rathiu ◽  
Mohammad Hosseini Fouladi ◽  
Satesh Narayana Namasivayam ◽  
Hasina Mamtaz
Keyword(s):  
Mathematical Model ◽  
Analytical Model ◽  
High Speed ◽  
Moving Load ◽  
Ground Vibration ◽  
Harmonic Excitation ◽  
Vibration Response ◽  
Vibration Velocity ◽  
Velocity Response ◽  
The Mathematical Model

Vibration of high-speed lines leads to annoyance of public and lowering real estate values near the railway lines. This hinders the development of railway infrastructures in urbanised areas. This paper investigates the vibration response of an isolated rail embankment system and modifies the component to better attenuate ground vibration. Mainly velocity response is used to compare the responses and the applied force is of 20 kN at excitation frequencies of 5.6 Hz and 8.3 Hz. Focus was made on ground-borne vibration and between the frequency range of 0 and 250 Hz. 3D Numerical model was made using SolidWork software and frequency response was produced using Harmonic Analysis module from ANSYS Workbench software. For analytical modelling MATLAB was used along with Simulink to verify the mathematical model. This paper also compares the vibration velocity decibels (VdB) of analytical two-degree of freedom model mathematical model with literature data. Harmonic excitation is used on the track to simulate the moving load of train. The results showed that modified analytical model gives the velocity response of 75 VdB at the maximum peak. Changes brought to the mass and spacing of the sleeper and to the thickness and the corresponding stiffness for the ballast does not result in significant vibration response. Limitations of two-degree analytical model is suspected to be the cause of this inactivity. But resonance vibration can be reduced with the aid of damping coefficient of rail pad. Statistical analysis methods t-test and ANOVA single factor test was used verify the values with 95% confidence.

Dynamic Model and Response of Robot Manipulators With Joint Irregularities

1993 ◽  
Vol 115 (1) ◽  
pp. 70-77 ◽  
Author(s):  
R. J. Chang ◽  
T. C. Jiang
Keyword(s):  
Mathematical Model ◽  
Dynamic Model ◽  
High Speed ◽  
Robotic Manipulator ◽  
Irregular Surface ◽  
Positioning Accuracy ◽  
Linearization Methods ◽  
Accuracy And Precision ◽  
Covariance Propagation ◽  
The Mathematical Model

The dynamic equation of a robotic manipulator with joint irregularities is formulated and employed for the prediction of the positioning accuracy and precision of a robotic manipulator in high-speed operation. The mathematical model is derived by incorporating a dynamic model of irregular joints in an ideal robotic equation and employing the Lagrangian formulation. The joint irregularity is modelled as an elastic sliding pair which consists of a journal with an irregular surface sliding on the surface of an elastic bearing. By employing Gaussian linearization methods, the operational accuracy and precision of the robotic manipulator are obtained from mean and covariance propagation equations of the robotic system. The operation of a single-arm robotic manipulator with joint irregularities is investigated for demonstrating the applications of the present techniques.

Optimal Design of Dynamic Secondary Cooling of Continuous Casting

2012 ◽  
Vol 472-475 ◽  
pp. 1907-1910
Author(s):  
Yi Wang ◽  
Xin Jian Ma
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Finite Element ◽  
Continuous Casting ◽  
Cooling System ◽  
Solidification Process ◽  
Element Model ◽  
Secondary Cooling ◽  
The Mathematical Model ◽  
The Finite Element Model

Numerical simulation of the secondary cooling is applied to the design of continuous casting. The mathematical model for solidification process of the strand under air-mist was established and calculated with the finite element model. The model is used to calculate the feasible operating range of the continuous casting machines. The dynamic secondary cooling system has been analyzed with consideration of the thermo mechanical principles and numerical model. The adequacy of the model has been confirmed with experimental results.

Acoustic response of high-speed deep groove ball bearing by modifying the internal geometry

2020 ◽  
pp. 146441932095511
Author(s):  
Deepak Borse ◽  
VB Tungikar
Keyword(s):  
Mathematical Model ◽  
Contact Stress ◽  
Noise Level ◽  
High Speed ◽  
Ball Bearing ◽  
Experimental Result ◽  
Acoustic Behaviour ◽  
Internal Geometry ◽  
Elliptical Contact ◽  
The Mathematical Model

In this paper, a mathematical model to predict acoustic responses of high-speed bearing has been developed and demonstrated in an application of Induction motors. Effect on the acoustic behaviour of bearing has studied by modifying the internal geometry, such as the number of rotating elements, curvature ratio, rotating speed with the oval shape of the track raceway due to pre-operational damage. The mathematical model predicts the contact stress, elliptical contact area, noise level dB and Frequencies of waviness pattern. High-speed bearing is tested at four different speeds to monitor acoustic behaviour. This drive end bearing undergoes different rotational speeds; however, the author has simulated the results at a majorly driven constant speed. The author has incorporated application-level testing at the customized test rig. The mathematical model has simulated using coupled governing equations with the help of the Ranga-Kutta method. The simulation and experimental results presented in this paper in the form of a waterfall diagram, FFT spectrum and colour pressure plots. Acoustic characteristics during measurements of the rolling bearing have shown systematically to correlate the mathematical model with an experimental result. Results indicate the remarkable influence of raceway nonconformities of bearing on the noise level. The novelty of research study is to estimate the amplitude of noise level due to waviness generated on rings of bearing after pre-operation damage which is the realistic scenario that occurred after a complaint recorded by the motor manufacturer. The authors believe that this technique enables the bearing designer to choose the appropriate diametric ratio of the ball and track curvature for elliptical contact stress as well as acoustic level. This method is developed specifically for an application of drive-end position ball bearing. Practical use of this method is to determine the Noise level of an electric motor (up to 60 kW capacities) due to improper handling and inappropriate installation of bearing which cause inherent waviness on components.

Mathematical modeling of articulated passenger train spatial vibrations

2021 ◽  
Vol 2021 (2) ◽  
pp. 91-99
Author(s):  
O. Markova ◽  
◽  
H. Kovtun ◽  
V. Maliy ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Ride Quality ◽  
Railway Transport ◽  
Passenger Train ◽  
Wide Range ◽  
Random Track Irregularities ◽  
The Mathematical Model

The problem of high-speed railway transport development is important for Ukraine. In many countries articulated trains are used for this purpose. As the connections between cars in such a train differ from each other, to investigate its dynamic characteristics not a separate car, but a full train vibrations model is necessary. The article is devoted to the development of the mathematical model for articulated passenger train spatial vibrations. The considered train consists of 7 cars: one motor-car, one transitional car, three articulated cars, one more transitional car and again one motor-car. Differential equations of the train motion along the track of arbitrary shape are set in the form of Lagrange’s equations of the second kind. All the necessary design features of the vehicles are taken into account. Articulated cars have common bogies with adjoining cars and a transfer car and the cars are united by the hinge. The operation of the central hinge between two cars is modeled using springs and dampers acting in the horizontal and vertical directions. Four dampers between two adjacent car-bodies act as dampers for pitching and hunting and are represented in the model by viscous damping. The system of 257 differential equations of the second order is set, which describes the articulated train motion along straight, curved, and transitional track segments with taking into account random track irregularities. On the basis of the obtained mathematical model the algorithm and computational software has been developed to simulate a wide range of cases including all possible combinations of parameters for the train elements and track technical state. The study of the train self-exited vibrations has shown the stable motion in all the range of the considered speeds (40 km/h – 180 km/h). The results obtained at the train motion along the track maintained for the speedy motion have shown that all the dynamic characteristics and ride quality index insure train safe motion and comfortable conditions for the travelling passengers.

Lapping Aspheric Workpiece Using Bending Method

2013 ◽  
Vol 331 ◽  
pp. 595-599
Author(s):  
Chun Min Shang ◽  
Dong Mei Zhang ◽  
Jian Dong Yang
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
New Method ◽  
Aspheric Surface ◽  
Shape Precision ◽  
Tool Shape ◽  
Forming Precision ◽  
Surface Precision ◽  
The Cost ◽  
The Mathematical Model

A new method is proposed that high speed lapping aspheric surface workpiece using lapping tool by means of bending because there processing difficult, In this study, the principle of high speed lapping has been presented, the mathematical model for the lapping tool has been established, and the equidistance curve error of the lapping tool has been analyzed. The results of the experiment indicate that the forming precision of the lapping tool is high using this method, the surface precision of the workpiece reaches micron grade, furthermore, the aspheric surface workpiece can been machined using this method in lapping, and that it can meet the need of medium precision of machining the aspheric surface workpiece. The experiment result indicates that the the lapping tool shape precision is high, the lapping error of the workpiece is 0.0108mm, and lapping efficiency is high and the cost is low. This aspheric lapping method has incomparable superiority of other processing methods.

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