The Design of Shock Absorbers for Chemical Equipments

2012 ◽  
Vol 479-481 ◽  
pp. 1283-1287
Author(s):  
Xin Yang ◽  
Xiao Yu Guo ◽  
Ming Liang Ding

A low cost shock absorber easy to install and tune was designed to solve the vibration problem produced by the compressor in chemical process. By establishing the mathematical model of the dynamic shock absorption, the shock absorber characteristics were analyzed theoretically. The preliminary experiment was conducted on the testing platform to simulate the factory conditions. The shock absorber was then installed on the compressor for the field validation. Testing results agree well with theory and the shock absorber showed good damping performance.

Author(s):  
S. G. Dzhamgarov ◽  
V. I. Oleynikov ◽  
V. A. Trudonoshin ◽  
V. G. Fedoruk

The article proposes a mathematical model of the aircraft landing upon touchdown operation. The mathematical model can be used at the early design stages to select the rational parameters of shock absorbers to ensure soft landing. Unlike most of the papers in the field concerned, it describes the simulation of the aircraft's run-out process rather than the first touchdown impact or Dynamic Drop Testing. This is due to the use of three-dimensional mathematical models of mechanical systems, including the aircraft body. In addition to the forces on the aircraft, the article gives a sufficiently detailed representation of the forces that arise in the shock absorber. The simulation results obtained using the PA8 complex developed at the CAD Department in Bauman Moscow State Technical University are presented. The diagrams presented show the effect of the clearance in the chambers of recovery stroke on the operation of shock absorbers and, as a consequence, on ensuring the soft landing conditions. An object-oriented approach, implemented in the complex, allows us to evaluate the influence of each element on the system dynamics. The article presents the time diagrams of the force of a gas spring taking into account the dry friction and the hydraulic force in the shock absorber. In conclusion, a rational, in authors’ opinion, approach to designing shock absorbers is shown. One of the points of this approach is the validation of shock absorber parameters based on the results of Dynamic Drop Testing and, after that, simulation of the aircraft landing with validated parameters. Such a technique will allow us to minimize the number of field experiments, and as a result, will shorten the design time and put the product into operation.


2013 ◽  
Vol 53 (1) ◽  
pp. 285
Author(s):  
Emile Barrett ◽  
Imran Abbasy ◽  
Chii-Rong Wu ◽  
Zhenjiang You ◽  
Pavel Bedrikovetsky

Estimation of rate profile along the well is important information for reservoir characterisation since it allows distinction of the production rates from different layers. The temperature and pressure sensors in a well are small and inexpensive; while flow meters are cumbersome and expensive, and affect the flow in the well. The method presented in this peer-reviewed paper shows its significance in predicting the gas rate from temperature and pressure data. A mathematical model for pressure and temperature distributions along a gas well has been developed. Temperature and pressure profiles from nine well intervals in field A (Cooper Basin, Australia) have been matched with the mathematical model to determine the flow rates from different layers in the well. The presented model considers the variables as functions of thermal properties at each location, which is more accurate and robust than previous methods. The results of tuning the mathematical model to the field data show good agreement with the model prediction. Simple and robust explicit formulae are derived for the effective estimation of flow rate and thermal conductivity in gas wells. The proposed approach has been applied to determine the well gas rate and formation thermal conductivity from the acquired well pressure and temperature data in field A. It allows for recommending well stimulation of layers with low production rates.


Author(s):  
Grzegorz Kopecki

The ability to carry out in-flight tests and to analyse the flight data registered is, in the case of aerospace engineering  students, a vital aspect of education. Since aircraft flight tests are very expensive, frequently the funds allocated to them in the process of education are insufficient. The aim of this article is to present a relatively low-cost method of training students to carry out flight tests and to analyse flight data. The method relies on three consecutive steps. At first, simulation tests relying on the mathematical model of an aircraft are carried out.  During these simulations, students analyse aircraft behaviour. Next, flight data registered during previously held in-flight tests are analysed.  Finally, flight tests are performed by students.  As a result, having mastered the ability to analyse real flight data, the students trained will become high-class specialists being able to conduct flight tests and analyse flight data.


2014 ◽  
Vol 635-637 ◽  
pp. 228-232
Author(s):  
Jian He ◽  
Ji Sheng Ma ◽  
Da Lin Wu

Airbag is widely used in heavy equipment dropped field with its efficient cushion performance and low cost. The calculation method used now for the process of airbag landing mainly is simulative calculation: analytical analysis and finite element simulation, but there are less systematic introduction for the mathematical model behind these methods in past papers. This paper mainly does the summary for the mathematical model of vented airbag which is usually used.


2013 ◽  
Vol 694-697 ◽  
pp. 36-40 ◽  
Author(s):  
Da Feng Song ◽  
Gong Ke Yang ◽  
Chun Xiao Du

On the basis of the structure characteristics of the seperated manually adjustable damper and its working principles, establish the shock absorber mathematical model, at the same time, get test data and curves of seperated manually adjustable shock absorber damping characteristics by bench test. Use MATLAB to simulate the characteristic curve of the speed of the shock absorber based on the mathematical model. The simulation curves and experimental curves were compared to verify the correctness and accuracy of the model. Further simulation and analysis affect of parts of structural changes on the damping characteristics. In order to provide a theoretical basis to structural parameters designing and vehicle damping matching.


Author(s):  
Carlos Velásquez-Villada ◽  
Yezid Donoso

Rural networking connectivity is a very dynamic and attractive research field. Nowadays big IT companies and many governments are working to help connect all these rural, disconnected people to Internet. This paper introduces a new routing algorithm that can bring non-real-time Internet connectivity to rural users. This solution is based on previously tested ideas, especially on Delay/Disruption Tolerant Networking technologies, since they can be used to transmit messages to and from difficult to access sites. It introduces the rural connectivity problem and its context. Then, it shows the proposed solution with its mathematical model used to describe the problem, its proposed heuristic, and its results. The advantage of our solution is that it is a low-cost technology that uses locally available infrastructure to reach even the most remote towns. The mathematical model describes the problem of transmitting messages from a rural, usually disconnected user, to an Internet connected node, through a non-reliable network using estimated delivery probabilities varying through time. The forwarding algorithm uses local knowledge gathered from interactions with other nodes, and it learns which nodes are more likely to connect in the future, and which nodes are more likely to deliver the messages to the destination. Our algorithm achieves an equal or better performance in delivery rate and delay than other well-known routing protocols for the rural scenarios tested. This paper adds more simulation results for the proposed rural scenarios, and it also extends the explanation of the mathematical model and the heuristic algorithm from the conference paper "Delay/Disruption Tolerant Networks Based Message Forwarding Algorithm for Rural Internet Connectivity Applications" [1] (doi: 10.1109/ICCCC. 2016.7496732).


2021 ◽  
Vol 7 ◽  
Author(s):  
Jorge de-J. Lozoya-Santos ◽  
Juan C. Tudon-Martinez ◽  
Ruben Morales-Menendez ◽  
Olivier Sename ◽  
Andrea Spaggiari ◽  
...  

A methodology is proposed for designing a mathematical model for shock absorbers; the proposal is guided by characteristic diagrams of the shock absorbers. These characteristic diagrams (Force-Displacement, Velocity-Acceleration) are easily constructed from experimental data generated by standard tests. By analyzing the diagrams at different frequencies of interest, they can be classified into one of seven patterns, to guide the design of a model. Finally, the identification of the mathematical model can be obtained using conventional algorithms. This methodology has generated highly non-linear models for 2 degrees of freedom magneto-rheological dampers with high precision (2–10% errors).


The proposed paper work is focused on the development of low cost six axis robot. The robot is modelled using mathematical model and it’s compared with the simulation model in the real time environment condition. The modeling of the robot is designed in the modeling software and it is simulated in the Matlab software. This type of solving system is used to solve the many type of real time problems. The simulated result is compared with the mathematical model of the robot. Based on the testing the robot is redesigned in the modeling software. In this work sin wave is given has input and the robot is followed the sine wave.


Author(s):  
S Cafferty ◽  
K Worden ◽  
G Tomlinson

In a previous paper [see reference (4)], it was shown that the restoring force surface (RFS) procedure provides a direct and clear method for characterizing the dynamic properties of automotive shock absorbers or dampers. The procedure was based on repetitive harmonic testing of the absorbers at fixed frequency but with varying amplitude. The current paper describes how the surfaces can be obtained from tests using random excitation. The merits and demerits are discussed relative to the harmonic test procedure. It is shown that the random excitation approach offers a useful alternative but produces force surfaces which are corrupted by small stochastic components; an explanation of the distortion is given in terms of the mathematical model proposed in the previous paper. The implications for identification of shock absorbers are discussed


Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 663
Author(s):  
Frank Florez ◽  
Pedro Fernández de Córdoba ◽  
John Taborda ◽  
Juan Carlos Castro-Palacio ◽  
José Luis Higón-Calvet ◽  
...  

Non-conventional thermal zones are low-cost and ecology friendly alternatives to the housing needs of populations in various situations, such as surviving natural disasters or addressing homelessness. However, it is necessary to guarantee thermal comfort for occupants, while aiming to minimize energy consumption and wastage in refrigeration systems. To reduce the cooling requirements in non-conventional thermal zones it is necessary to model the structure and analyze the principal factors contributing to internal temperature. In this paper, a geodesic dome is modellingusing the lumped parameter technique. This structure is composed of a wooden skeleton and wooden floor, with a canvas surface as its exterior. The mathematical model was tuned using experimental data, and its parameters were classified using Monte Carlo sensitivity analysis. The mathematical model was used to evaluate the impact on internal temperature and occupants’ comfort when two strategies are considered. The results obtained indicatee internal temperature reductions down to a range of 7% to 11%; this result is reflected directly in the energy used to refrigerate the thermal zone, contributing to the objective of providing houses with lower energy consumption.


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