Study on Computer Simulation for Car Handling Dynamics with 8 DOF

2013 ◽  
Vol 655-657 ◽  
pp. 1136-1140
Author(s):  
Peng Zhang ◽  
Le He ◽  
Xu Tao Liu ◽  
Qun Sheng Xia

A mathematical model of eight degrees freedom was built up with considering the normal load transfer due to the presence of the longitudinal, lateral acceleration for a vehicle under braking in turn condition. And the simulation model based on the mathematical model was eatablished by means of MATLAB/Simulink software. The comparison between simulation results and real vehicle test results under the snow pavement double-lane change condition is in good agreement. It can be concluded that the 8DOF vehicle dynamics model of this study is acceptable and valid.

2013 ◽  
Vol 749 ◽  
pp. 633-642
Author(s):  
Zhao Fang ◽  
Peng Fei Xu ◽  
Jian Xu ◽  
Lin Bo Li ◽  
Jun Zhu

Electrolysis expansion of carbon cathodes due to alkali metal penetration in [K3AlF6/Na3AlF6]-AlF3-Al2O3 melts was tested. Effect of ampere density and superheating temperature on the electrolysis expansion was studied. A mathematical model was got to numerically describe electrolysis expansion performance of carbon cathode. The results indicated that K and Na penetrate into carbon cathode from outside to inside. Ampere density and superheating temperature had a great effect on the electrolysis expansion of carbon cathode. With the superheating temperature increasing from 10 to 50, electrolysis expansion increased from 1.41% to 2.10% gradually. With the ampere density increasing, the increase trend of electrolysis expansion was not linear. When ampere density was lower than 0.4A / cm2 and greater than 0.7A / cm2, cathode electrolysis expansion obviously increased with the increase of ampere density. Meanwhile, cathode electrolysis expansion tended to be constant as the ampere density changed at the range of 0.4A / cm2 to 0.7A / cm2.The results of the mathematical model in this study had a good agreement with the test results. This model would be helpful to accurately describe the anti-penetration performance of K and Na on the carbon cathode.


Author(s):  
W M G Malalasekera ◽  
F Lockwood

A mathematical model has been applied to simulate model experiments of the 1987 King's Cross underground fire by the Department of Health and Safety Executive. The predicted growth of the fire is compared with the experimental data and in particular the predicted and measured times to ‘flashover’ are compared. The comparisons show exceptional agreement which, in part, may be fortuitous due to the need to facilitate the prediction of the early stages of the growth with the aid of an experimentally estimated fire strength. The good agreement nonetheless is also due to the full description of the radiation transfer which is a feature of the mathematical model. It is concluded that the flashover phenomenon that occurred at King's Cross was thermal radiation driven and that future research should be devoted to modelling the details of fire spread across a combustible surface.


1999 ◽  
Vol 66 (4) ◽  
pp. 926-933 ◽  
Author(s):  
T. A. Godfrey ◽  
J. N. Rossettos

A simple micromechanical model is developed to predict the onset of tear propagation at slit-like damage sites (i.e., a series of consecutive aligned yarn breaks) in biaxially stressed plain weave fabrics under increasing loading. A crucial aspect of the model is the treatment of the frictional slip of yarns near the damage site. Although the actual configuration of slipping regions is complex, the onset of tear propagation in large slits (i.e., more than, say, 35 breaks) is dominated by slip occurring on the first few intact yarns adjacent to the breaks. The assumptions in the mathematical model were motivated by both experimental observations and calculations for key configurations. Analytical results obtained for this simple model exhibit good agreement with experimental results, which are presented for a variety of fabrics with initial slits of 35 and 45 breaks.


2021 ◽  
pp. 0734242X2110337
Author(s):  
Tea Sokač ◽  
Anita Šalić ◽  
Dajana Kučić Grgić ◽  
Monika Šabić Runjavec ◽  
Marijana Vidaković ◽  
...  

In this paper, two different types of biowaste composting processes were carried out – composting without and with bioaugmentation. All experiments were performed in an adiabatic reactor for 14 days. Composting enhanced with bioaugmentation was the better choice because the thermophilic phase was achieved earlier, making the composting time shorter. Additionally, a higher conversion of substrate (amount of substrate consumed) was also noticed in the process enhanced by bioaugmentation. A mathematical model was developed and process parameters were estimated in order to optimize the composting process. Based on good agreement between experimental data and the mathematical model simulation results, a three-level-four-factor Box-Behnken experimental design was employed to define the optimal process conditions for further studies. It was found that the air flow rate and the mass fraction of the substrate have the most significant effect on the composting process. An improvement of the composting process was achieved after altering the mentioned variables, resulting in shorter composting time and higher conversion of the substrate.


2021 ◽  
pp. 43-54
Author(s):  
A. N. Krutov ◽  
◽  
S. Ya. Shkol’nikov ◽  

The mathematical model of kinematic wave, that is widely used in hydrological calculations, is generalized to compute processes in deformable channels. Self-similar solutions to the kinematic wave equations, namely, the discontinuous wave of increase and the “simple” wave of decrease are generalized. A numerical method is proposed for solving the kinematic wave equations for deformable channels. The comparison of calculation results with self-similar solutions revealed a good agreement.


Author(s):  
Stanislav N. Danov

Abstract Several improvements to the mathematical model of the indicator process taking place at a diesel engine cylinder are proposed. The thermodynamic behavior of working medium is described by the equation of state, valid for real gases. Mathematical dependencies between thermal parameters (P, T, v) and caloric parameters (u, h, cv, cp) have been obtained. An improved mathematical model, based on the first law of thermodynamics, has been developed, taking into account working medium imperfections. The numerical solution of the simultaneous differential equations is made by a method of Runge-Kutta type. The computing procedure is iterative. Calculations in respect to the caloric parameters (u, h, cv and cp) for various gases under pressure up to 25 MPa and temperature up to 3000°C have been carried out. The results show, that there are significant differences between the values, calculated by equations for ideal gases, and the proposed equations for real gases under high pressure and temperature. Actual applied problems for two-stroke turbocharged engines Sulzer-RLB66 and 8DKRN 74/160 have been solved. The comparison between the experimental data and numerical results show very good agreement. The numerical experiments show that if the pressure is above 8–9 MPa, the working medium imperfections must be taken into consideration.


2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Ibrahim A Abuashe ◽  
Bashir H Arebi ◽  
Essaied M Shuia

A mathematical model based on the momentum, continuity and energy balance equations was developed to simulate the behavior of the air flow inside the solar chimney system. The model can estimate the power output and performance of solar chimney systems. The developed mathematical model is validated by the experimental data that were collected from small pilot solar chimney; (experiment was presented in part I). Good agreement was obtained between the experimental results and that from the mathematical model. The model can be used to analyze the solar chimney systems and to determine the effect of geometrical parameters such as chimney height and collector diameter on the power output and the efficiency of the system


Author(s):  
R. Caracciolo ◽  
A. Gasparetto ◽  
A. Trevisani

Abstract This paper presents an experimental validation of a finite element approach for the dynamic analysis of flexible multi-body planar mechanisms. The mathematical model employed accounts for mechanism geometric and inertial non-linearities and considers coupling effects among rigid-body and elastic motion. A flexible five-bar linkage actuated by two electric motors is employed as a test case. Experimentally determined link absolute deformations are compared with the numerical results obtained simulating the system dynamic behavior through the mathematical model. The experimental and numerical results are in good agreement especially after the very first transient period.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yi Wei ◽  
Shuilong He ◽  
Enyong Xu ◽  
Genge Zhang ◽  
Rongjiang Tang ◽  
...  

To master the basic characteristics of steady-state cornering for a semitrailer, this paper summarises the current modelling methods for handling and stability and discusses their limitations. The classical linear mathematical model for a two-degree-of-freedom (DOF) handling and stability system is used to develop a new model. Analysis methods are proposed to introduce the influence of the camber angle and body roll into the model parameters. Thus, a mathematical model for the lateral stability of semitrailer with five DOFs is established. At the same time, a modified formula to calculate the stability factor of the semitrailer is developed with a MATLAB model to solve the dynamic state equation. The mathematical model, which considers the body roll and the changes in the camber angle caused by roll, compares the turning radius ratio and yaw rate as the evaluation index with the classical linear mathematical model of a two-DOF system. The vehicle parameters for three different types of semi-tractor trailers are used to calculate and compare two mathematical models for handling and stability using real vehicle test data. The results show that the new modelling and analysis method proposed in this paper has a high calculation accuracy and fast calculation speed, is clear and concise, and is consistent with the real vehicle test data. In addition, the accuracy of the new mathematical model for handling and stability and the improved stability factor are verified.


Author(s):  
О.Ф. Воропаева ◽  
O.F. Voropaeva

The mathematical model of the dynamics of the tumor markers network p53–Mdm2–microRNA for microRNA class with a direct positive connection with p53 was formulated. Numerical investigation of the microRNA functioning in conditions of the deregulation of p53 and p53–Mdm2-network was carried out. The deregulation of microRNA in detail was studied. The situations in which p53, its inhibitor Mdm2 and microRNAs exhibit critical properties for the patient's status and can be identified as diagnostic markers of cancer and neurodegenerative disease were studied. The results of numerical analysis are in good agreement with the data of clinical and laboratory studies of known microRNAs.


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