Performance and Stability Analysis of a High-Speed Jet using Multi-Disciplinary Approach

2021 ◽  
Author(s):  
Shuaib Salamat ◽  
Irsalan Arif ◽  
Hassan Raza
Author(s):  
Nur Alyani Nadhiya ◽  
Fitri Yakub ◽  
Hatta Ariff ◽  
Azizul Azizan ◽  
Zainuddin A. Rasit ◽  
...  

2016 ◽  
Vol 68 (3) ◽  
pp. 386-391 ◽  
Author(s):  
Abhishek Ghosh ◽  
Sisir Kumar Guha

Purpose Several researchers have observed that to satisfy modern day’s need, it is essential to enhance the characteristics of journal bearing, which is used in numerous applications. Moreover, the use of Newtonian fluid as a lubricant is diminishing day by day, and the use of Non-Newtonian fluids is coming more into picture. Furthermore, if turbo-machinery applications are taken into account, then it can be seen that journal bearings are used for high speed applications as well. Thus, neglecting turbulent conditions may lead to erroneous results. Hence, this paper aims to present focuses on studying the stability characteristics of finite hydrodynamic journal bearing under turbulent coupled-stress lubrication. Design/methodology/approach First, the governing equation relevant to the problem is generated. Then, the dynamic analysis is carried out by linear perturbation technique, leading to three perturbed equations, which are again discretized by finite difference method. Finally, these discretized equations are solved with the help of Gauss-Seidel Iteration technique with successive over relaxation scheme. Consequently, the film response coefficients and the stability parameters are evaluated at different parametric conditions. Findings It has been concluded from the study that with increase in value of the coupled-stress parameter, the stability of the journal may increase. Whereas, with increase in Reynolds number, the stability of the journal decreases. On the other hand, stability increases with increasing values of slenderness ratio. Originality/value Researches have been performed to study the dynamic characteristics of journal bearing with non-Newtonian fluid as the lubricant. But in the class of non-Newtonian lubricants, the use of coupled-stress fluid has not yet been properly investigated. So, an attempt has been made to perform the stability analysis of bearings with coupled-stress fluid as the advanced lubricant.


2013 ◽  
Vol 392 ◽  
pp. 156-160
Author(s):  
Ju Seok Kang

Multibody dynamics analysis is advantageous in that it uses real dimensions and design parameters. In this study, the stability analysis of a railway vehicle based on multibody dynamics analysis is presented. The equations for the contact points and contact forces between the wheel and the rail are derived using a wheelset model. The dynamics equations of the wheelset are combined with the dynamics equations of the other parts of the railway vehicle, which are obtained by general multibody dynamics analysis. The equations of motion of the railway vehicle are linearized by using the perturbation method. The eigenvalues of these linear dynamics equations are calculated and the critical speed is found.


2010 ◽  
Vol 43 ◽  
pp. 492-498
Author(s):  
Zi Xiong Lin ◽  
Xiang Huang ◽  
Muhammad Masud Akhtar

Significant research has been made regarding chatter stability of milling operations. This paper presents a 2 degree of freedom stability analysis model (2 DOF model) for interrupted cutting. The cutting process is divided into two parts namely “free vibration” and “forced vibration” considering the flexibility in x and y directions. Calculating the solutions of the two parts, a four-dimensional-single-variation discretization map is established and the eigenvalues of the Jacques Matrix are checked at the fixed point on the Floquet unit circle. The two Neimark-Sacker and flip bifurcations are evaluated. The research work shows that the up milling is more stable than the down milling under the same operating parameters. The comprison of the proposed 2 DOF model with Davies one degree of dimensional model (1 DOF Davieas model) has been made in the paper which shows that the area of stable region in the proposed model is greater than the stable region in the 1 DOF Davies model. In the last the results of the experiments support the proposed model has been verified by experimentation.


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