THE IMPACT OF THE DIMENSION OF A MATHEMATICAL MODEL OF INTERNAL BALLISTICS ON DESIGN PARAMETERS OF A SHOT FOR GRAIN GUNPOWDER CHARGES

2021 ◽  
pp. 95-110
Author(s):  
I.G. Rusyak ◽  
◽  
V.A. Tenenev ◽  
Keyword(s):  
Mathematical Model ◽  
Powder Mixture ◽  
Thermodynamic Model ◽  
Dynamic Models ◽  
Design Parameters ◽  
Variable Cross ◽  
One Dimensional ◽  
Gas Dynamic ◽  
Wide Range ◽  
The Impact

The problem of the impact of the mathematical model dimension on the calculated intraballistic characteristics of a shot for the charges made of granulated powder is considered. Mathematical models of the shot are studied using the spatial (axisymmetric), one-dimensional, and zero-dimensional (thermodynamic) formulations. The thermodynamic model takes into account the distribution of the pressure and velocity of a gas-powder mixture behind the shot for a channel of variable cross-section. Comparison of simulation results is carried out in a wide range of loading parameters. It is shown that there is a range of the loading parameters for a thermodynamic approach to give satisfactory approximation to the parameters obtained using the gas-dynamic approach, which describes the flow of a heterogeneous reacting mixture with a separate consideration of phases and intergranular interactions between them. Notably that in the entire range of the charging parameters studied in this work, the one-dimensional and twodimensional gas-dynamic models only slightly differ from each other. Therefore, in the main pyrodynamic period, the actuation of the charge, made of granulated powder, can be simulated using a one-dimensional gas-dynamic model or a zero-dimensional thermodynamic model with allowance for spatial distribution of the pressure and velocity of the gas-powder mixture.

scholarly journals Simulation Tests of a Cow Milking Machine—Analysis of Design Parameters

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1358
Author(s):  
Ewa Golisz ◽  
Adam Kupczyk ◽  
Maria Majkowska ◽  
Jędrzej Trajer
Keyword(s):  
Mathematical Model ◽  
Simplified Model ◽  
Design Parameters ◽  
Degree Polynomial ◽  
Fourth Degree ◽  
Local Loss ◽  
Linear Drag ◽  
Milking Machine ◽  
Machine Analysis ◽  
The Impact

The objective of this paper was to create a mathematical model of vacuum drops in a form that enables the testing of the impact of design parameters of a milking cluster on the values of vacuum drops in the claw. Simulation tests of the milking cluster were conducted, with the use of a simplified model of vacuum drops in the form of a fourth-degree polynomial. Sensitivity analysis and a simulation of a model with a simplified structure of vacuum drops in the claw were carried out. As a result, the impact of the milking machine’s design parameters on the milking process could be analysed. The results showed that a change in the local loss and linear drag coefficient in the long milk duct will have a lower impact on vacuum drops if a smaller flux of inlet air, a higher head of the air/liquid mix, and a higher diameter of the long milk tube are used.

Performance Modeling of Desiccant Wheels: 1 — Model Development

2008 ◽  
Author(s):  
Chaoqin Zhai ◽  
David H. Archer ◽  
John C. Fischer
Keyword(s):  
Model Development ◽  
Axial Direction ◽  
Performance Model ◽  
Design Parameters ◽  
Residual Water ◽  
One Dimensional ◽  
Operating Variables ◽  
Steady State Operation ◽  
Rotary Speed ◽  
The Impact

This paper presents the development of an equation based model to simulate the combined heat and mass transfer in the desiccant wheels. The performance model is one dimensional in the axial direction. It applies a lumped formulation in the thickness direction of the desiccant and the substrate. The boundary conditions of this problem represent the inlet outside/process and building exhaust/regeneration air conditions as well as the adiabatic condition of the two ends of the desiccant composite. The solutions of this model are iterated until the wheel reaches periodic steady state operation. The modeling results are obtained as the changes of the outside/process and building exhaust/regeneration air conditions along the wheel depth and the wheel rotation. This performance model relates the wheel’s design parameters, such as the wheel dimension, the channel size and the desiccant properties, and the wheel’s operating variables, such as the rotary speed and the regeneration air flowrate, to its operating performance. The impact of some practical issues, such as wheel purge, residual water in the desiccant and the wheel supporting structure, on the wheel performance has also been investigated.

scholarly journals A STUDY OF THE DEFLECTIONS OF METAL ROAD GUARDRAIL ELEMENTS

Transport ◽  
2009 ◽  
Vol 24 (3) ◽  
pp. 225-233 ◽  
Author(s):  
Olegas Prentkovskis ◽  
Andrey Beljatynskij ◽  
Rasa Prentkovskienė ◽  
Ivan Dyakov ◽  
Laima Dabulevičienė
Keyword(s):  
Mathematical Model ◽  
Finite Elements ◽  
Traffic Accidents ◽  
Statistical Data ◽  
Elastic Deformations ◽  
One Dimensional ◽  
First Order ◽  
Horizontal Beam ◽  
Deformation Processes ◽  
The Impact

Statistical data on traffic accidents in 2008 in Lithuania is presented. Referring to statistical data, grounding on an obstacle’ makes one‐tenth of all registered traffic accidents ‐ 9.4% (an obstacle may be a road guardrail, a lamp post, a tree, a bar, a gate, etc.). Road guardrails of various types are installed on the shoulders and dividing strips of urban and suburban roads. They are as follows: reinforced concrete guardrails, cable guardrails and metal guardrails. Metal guardrails, consisting of S‐shape metal posts and a protective W‐shape horizontal beam, are most popular. The authors of the present paper examine the deformation processes of the elements of the above mentioned guardrail. A mathematical model of metal road guardrail was developed. Metal road guardrail was modelled using one‐dimensional first‐order finite elements, taking into account only elastic deformations, as well as the effect of soil on the buried post section of the guardrail. Based on the developed mathematical model of metal road guardrail, the deflections of its elements caused by the impact of a vehicle moving at varying speed were determined. The obtained values of deflections of guardrail elements (a protective W‐shape horizontal beam and a S‐shape post) presented in paper do not exceed the admissible values (of beam deflections).

Dynamic Behavior of Piezoelectric Recurve Actuation Architectures

2004 ◽  
Vol 126 (1) ◽  
pp. 37-46 ◽  
Author(s):  
James D. Ervin ◽  
Diann E. Brei
Keyword(s):  
Dynamic Behavior ◽  
Architectural Design ◽  
Dynamic Models ◽  
Dynamic Performance ◽  
Design Parameters ◽  
New Family ◽  
State Frequency ◽  
Actuation Scheme ◽  
The Impact ◽  
High Work

A new family of piezoelectric actuators, called Recurves, exhibits high work per volume and have the extra benefit of performance and packaging tailorability. The focus of this paper is the dynamic performance of this novel actuation scheme. Two dynamic models, a detailed transfer matrix model and a simpler rod approximation model, are presented to predict the steady state frequency response of a general Recurve actuator driving a mass and spring load. Results from a 23 design of experiments are given that validate these models and demonstrate the impact of the architectural design parameters on the dynamic behavior of a generic Recurve actuator.

Discrete modular serpentine robotic tail: design, analysis and experimentation

Robotica ◽  
2018 ◽  
Vol 36 (7) ◽  
pp. 994-1018 ◽  
Author(s):  
Wael Saab ◽  
William S. Rone ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Dynamic Models ◽  
Design Analysis ◽  
Degree Of Freedom ◽  
Legged Robots ◽  
Design Parameters ◽  
Inertial Loading ◽  
Forward Kinematic ◽  
The Impact ◽  
Accuracy And Repeatability ◽  
Two Degree Of Freedom

SUMMARYThis paper presents the design, analysis and experimentation of a Discrete Modular Serpentine Tail (DMST). The mechanism is envisioned for use as a robotic tail integrated onto mobile legged robots to provide a means, separate from the legs, to aid stabilization and maneuvering for both static and dynamic applications. The DMST is a modular two-degree-of-freedom (DOF) articulated, under-actuated mechanism, inspired by continuum and serpentine robotic structures. It is constructed from rigid links with cylindrical contoured grooves that act as pulleys to route and maintain equal displacements in antagonistic cable pairs that are connected to a multi-diameter pulley. Spatial tail curvatures are produced by adding a roll-DOF to rotate the bending plane of the planar tail curvatures. Kinematic and dynamic models of the cable-driven mechanism are developed to analyze the impact of trajectory and design parameters on the loading profiles transferred through the tail base. Experiments using a prototype are performed to validate the forward kinematic and dynamic models, determine the mechanism's accuracy and repeatability, and measure the mechanism's ability to generate inertial loading.

scholarly journals A one-dimensional model for tidal array design based on three-scale dynamics

2017 ◽  
Vol 825 ◽  
pp. 651-676 ◽  
Author(s):  
Vikrant Gupta ◽  
Anna M. Young
Keyword(s):  
Surface Deformation ◽  
Channel Length ◽  
Design Parameters ◽  
Tidal Channels ◽  
Tidal Current Energy ◽  
Array Design ◽  
One Dimensional ◽  
Power Extraction ◽  
The Impact ◽  
Current Energy

In order to make the extraction of tidal current energy economically viable, the power production per turbine must be optimised in each tidal array. Furthermore, the impact of power extraction on the marine flow environment must be understood. These two aims mean that designers must be able to model different configurations of a tidal array in order to create the most efficient, least invasive arrangement. In this paper, an analytical model is developed for array design in idealised rectangular tidal channels with idealised turbines. The model includes the effects of (i) local blockage, (ii) surface deformation and (iii) added drag due to the installation of the array. While these effects have been accounted for individually in past work, the model presented here is the first to include all three such that the interaction between different effects can be understood. Results are presented for optimal local blockage and turbine resistance as functions of inherent channel drag coefficient, channel length and Froude number at various global blockage values. It will be shown that it is necessary to model the effects of local blockage and added drag simultaneously in order to obtain the design parameters of a tidal array (global blockage, local blockage and turbine resistance), which will maximise the power extraction per turbine. Neglecting either effect will lead to an array design with lower power extraction than the optimum, the addition of unnecessary extra turbines and higher lost power from the array.

Experimental study of passive vibration suppression using absorber with spherical ball impact damper

2016 ◽  
Vol 231 (17) ◽  
pp. 3193-3201 ◽  
Author(s):  
Riadh Chaari ◽  
Fathi Djemal ◽  
Fakher Chaari ◽  
Mohamed Slim Abbes ◽  
Mohamed Haddar
Keyword(s):  
Vibration Suppression ◽  
Industrial Applications ◽  
Design Parameters ◽  
Particle Impact ◽  
Ball Impact ◽  
Impact Damper ◽  
Ball Size ◽  
Wide Range ◽  
The Impact ◽  
Impact Damping

Impact dampers are efficient in many industrial applications with a wide range of frequencies. An experimental analysis of the impact damping of spherical balls is investigated to simplify the particle impact damping design and improve the vibration suppression. The objective of the study is to analyze some of the design parameters of impact damper using spherical balls. The experimental investigation consists to test the effect of the ball size for each mass level, the number of balls for each size level and different exciting force levels on vibrations of the main structure. The parametric study provided useful information to understand and optimize Particle Impact Damping design.

scholarly journals Photonic Crystal Enhanced by Metamaterial for Measuring Electric Permittivity in GHz Range

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 416
Author(s):  
Arafa H. Aly ◽  
Ayman A. Ameen ◽  
M. A. Mahmoud ◽  
Z. S. Matar ◽  
M. Al-Dossari ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Data Transfer ◽  
Defect Layer ◽  
5G Networks ◽  
One Dimensional ◽  
Design Structure ◽  
Wide Range ◽  
Main Component ◽  
The Impact

The rise of broadband cellular networks and 5G networks enable new rates of data transfer. This paper introduces a new design to measure the permittivity in the GHz range of non-magnetic materials. We tested the proposed design with a wide range of materials such as wood, glass, dry concrete, and limestone. The newly proposed design structure has a maximum sensitivity of 0.496 GHz/RIU. Moreover, it can measure permittivities in the range from 1 up to 9. The main component of the designed structure is a defective one-dimensional photonic crystal with a unit cell consisting of metamaterial and silicon. In addition, we demonstrate the role of the metamaterial in enhancing the proposed design and examine the impact of the defect layer thickness on the proposed structure.

Modeling and Experimental Characterization of the Dynamic Behavior of Piezoelectric Recurve Actuation Architectures

1999 ◽  
Author(s):  
James D. Ervin ◽  
Diann E. Brei
Keyword(s):  
Dynamic Behavior ◽  
Architectural Design ◽  
Dynamic Models ◽  
Dynamic Performance ◽  
Design Parameters ◽  
New Family ◽  
State Frequency ◽  
Actuation Scheme ◽  
The Impact

Abstract There are numerous applications that require fast actuators to deliver specific force and displacement output while fitting into confined spaces. A new family of piezoelectric actuators called Recurves exhibit high work per volume and have the extra benefit of having both the force-deflection performance and packaging tailorable to fit the requirements of a given application. The focus of this paper is the dynamic performance of this novel actuation scheme. Two dynamic models, a detailed transfer matrix model and a simpler rod approximation model, are presented to predict the steady state frequency response of a general Recurve actuator driving a mass and spring load. Results from a 23 design of experiments are given that validate these models and demonstrate the impact of the architectural design parameters on the dynamic behavior of the general Recurve actuator.

Investigation of the Influence of Consequential Design Parameters on the Mechanical Performance of Biodegradable Bone Scaffolds, Fabricated Using Pneumatic Micro-Extrusion Additive Manufacturing Process

2020 ◽  
Author(s):  
Daguan Zhao ◽  
Mohan Yu ◽  
Logan Lawrence ◽  
Pier Paolo Claudio ◽  
James B. Day ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
High Resolution ◽  
Functional Properties ◽  
Manufacturing Process ◽  
Design Parameters ◽  
Bone Scaffolds ◽  
Material Deposition ◽  
Wide Range ◽  
The Impact

Abstract Pneumatic micro-extrusion (PME) is a high-resolution direct-write additive manufacturing process, which has emerged as the process of choice for tissue engineering and biofabrication of a broad spectrum of organs and tissues (e.g., bone, aortic valve, blood vessels, human ear, and nose). Despite the advantages and host of biomedical applications engendered by the PME process — including, for example, (i) accommodation of a wide range of material viscosity (enabled via thermopneumatic material deposition), (ii) large build volume and standoff distance for tissue engineering, (iii) in situ UV curing, and (iv) high-resolution multimaterial deposition — there are intrinsically complex design, material, and process factors as well as interactions, which influence the functional properties of PME-fabricated tissues and organs. Consequently, investigation of the impact and interaction of each factor aligned with establishment of a physics-based, optimal material deposition regime is inevitably a burgeoning need. In this study, using the Taguchi design, the influence of four significant factors, i.e., layer height, infill density, infill pattern, and print speed, is investigated on the compression properties as well as the dimensional accuracy of polycaprolactone (PCL) bone scaffolds, fabricated using the PME process. Furthermore, a 3D, transient two-phase flow CFD model is forwarded with the aim to observe the flow of material within the deposition head as well as the micro-capillary (nozzle). The results of this study pave the way for further investigation of the bio-functional properties of bone scaffolds, e.g., biodegradation, cell proliferation and growth rate.

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