scholarly journals Rational design for a friction unit of a disc-shoe brake

2021 ◽  
Vol 25 (3) ◽  
pp. 309-319
Author(s):  
A. E. Litvinov ◽  
P. A. Polyakov ◽  
A. A. Golikov ◽  
N. A. Zadayanchuk
Keyword(s):  
Rational Design ◽  
Design Method ◽  
Friction Pair ◽  
Thermal Stabilization ◽  
Design Stage ◽  
Design Parameters ◽  
Friction Unit ◽  
Brake Disc ◽  
Operational Parameters ◽  
Preliminary Calculation

In this study, we develop a rational design for a friction unit provided that restrictions are imposed on the fly-wheel masses of rotating elements and the onset of a thermal stabilization state. The input calculation data were the braking torque, specific pressure in the friction pair, angular velocity and the diameter of the brake disc hub. The geometric programming method was used at the preliminary stage to calculate the design and operational parameters of a discshoe brake. Further, the parameters were refined based on the conditions of mutually exclusive factors (energy intensity and braking time) and the stress-strain state. On the basis of the proposed rational design for a friction unit, a software application for calculating in the DELPHI programming language was developed. The ranges of design parameters were determined at the preliminary design stage: a brake disc diameter from 0.237 to 0.37 m; the width of working surfaces from 0.0335 to 0.1 m; and the thickness of half-discs from 0.012 to 0.026 m. The final result of the rational design method was the specified ranges of design parameters: diameter from 0.31 to 0.324 m; width from 0.041 to 0.0485 m; and thickness from 0.0148 to 0.0151 m. The developed method of rational design reduces the diameter ranges of the designed brake disc in comparison with the preliminary calculation by 9.5 times, while the ranges of the width of the working surfaces are reduced by 8.9 times, and the thickness range – by 46.6 times. At the final stage, the secondary design and operational parameters of the friction unit were determined: the areas of the working and non-working surfaces of the friction pairs and the coefficient of their mutual overlap. The proposed method of rational design reduces the selected range of design parameters, which will provide a more rational choice of compliance with their specified performance characteristics.

scholarly journals VORTEX DEVICES OF THE DIESEL AIR SUPPLY SYSTEM: MATHEMATICAL MODEL OF AERODYNAMIC PROCESSES

2020 ◽  
Vol 17 (1) ◽  
pp. 110-120
Author(s):  
R. V. Yakimushkin
Keyword(s):  
Mathematical Model ◽  
Rational Design ◽  
Particle Dynamics ◽  
Supply System ◽  
Design Stage ◽  
Design Parameters ◽  
Classical Dynamics ◽  
Effective Parameters ◽  
Air Supply ◽  
Dynamics Method

Introduction. The calculation of effective indicators of the vortex ejector used in the diesel air supply system is a pressing task as it allows significantly reducing time for determination of rational design parameters at the design stage. One of the modifications of the particle dynamics method is a promising direction, allowing with high physical adequacy, “from the first principles,” to model aerodynamic processes in vortex devices. Therefore, the purpose of the paper is to develop a mathematical model of a vortex ejector.Materials and methods. The paper discussed a method of the mathematical simulation of ejection and ejection flows in a vortex ejector. The proposed modification of the particle dynamics method allowed describing aerodynamic processes with the help of simple laws of classical dynamics, and modeling them with the help of software of the Delphi 7 System. The author presented differential equations, which were solved by the Runge-Kutt method of the second order. As a result of the solution, the authors determined paths of air elements movement in the vortex ejector, which allowed estimating effective parameters of vortex devices.Results. To study the model, the author developed a program with the possibility to set geometric parameters of the vortex ejector in the interface window and to display the current values of the process parameters.Discussion and conclusions. Proposed mathematical model and computer program make it possible to quantify efficiency of vortex devices at their design stage. The advantage of the proposed mathematical model lies in more accurate calculation of vortex flow parameters from the vortex ejector design and physical properties of ejecting and ejecting flows.Financial transparency: the author has no financial interest in the presented materials or methods. There is no conflict of interest.

Factors Affecting the Power-Efficient Operation of Wind-Diesel Complexes

2019 ◽  
pp. 229-266
Author(s):  
Dmitry Chernov ◽  
Galina Deryugina ◽  
Nikita Karpov ◽  
Mikhail Tyagunov ◽  
Haiyang He
Keyword(s):  
Energy Efficiency ◽  
Capacity Utilization ◽  
Parameters Estimation ◽  
Design Stage ◽  
Design Parameters ◽  
Operational Parameters ◽  
Power Efficient ◽  
Factors Affecting ◽  
City District ◽  
Preliminary Design Stage

The purpose of this chapter is to compare the design and operational parameters of energy efficiency (power generation, capacity utilization factor) of a wind power plant (WPP) in order to improve the accuracy of the design parameters estimation at the preliminary design stage. Recommendations have been given for accounting different factors influencing on energy efficiency and economic indicators of a WPP. In this chapter, the research is carried out on the example of existing wind-diesel complexes (WDC) in the settlement of Ust-Kamchatsk (Kamchatka Krai), Novikovo (Sakhalin Oblast), and projected WDC on Popova Island (Vladivostok city district).

scholarly journals Minimization of Stress State of a Hub of Friction Pair

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Vagif M. Mirsalimov ◽  
Parvana E. Akhundova
Keyword(s):  
Stress State ◽  
Friction Pair ◽  
Circumferential Stress ◽  
Design Stage ◽  
Friction Unit ◽  
Surface Model ◽  
Oil Well ◽  
Algebraic Equations ◽  
Minimax Criterion ◽  
External Contour

The function of displacements of external contour points of a friction pair hub that could provide minimization of stress state of a hub was determined on the basis of minimax criterion. The problem is to decrease stress state at that place where it is important. The rough friction surface model is used. To solve a problem of optimal design of friction unit the closed system of algebraic equations is constructed. Increase of serviceability of friction pair parts may be controlled by design-engineering methods, in particular by geometry of triboconjugation elements. Minimization of maximum circumferential stress on contact surface of friction unit is of great importance in the design stage for increasing the serviceability of friction pair. The obtained function of displacements of the hub’s external contour points provides the serviceability of friction pair elements. The calculation of friction pair for oil-well sucker-rod pumps is considered as an example.

scholarly journals Rational Design Method Based on Techno-Economic Principles for Integration of Organic/Organic Pervaporation with Lipase Catalyzed Transesterification

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 407
Author(s):  
Wouter Van Hecke ◽  
Pieterjan Debergh ◽  
Mohammed Nazeer Khan ◽  
Miet Van Dael
Keyword(s):  
Rational Design ◽  
Reaction Rate ◽  
Methyl Acetate ◽  
Design Method ◽  
Membrane Surface ◽  
Economic Assessment ◽  
Geranyl Acetate ◽  
Design Parameters ◽  
Trial And Error ◽  
Enzyme Loading

An engineering foundation is developed in this manuscript to allow the rational design of enzymatic transesterifications integrated with organic–organic pervaporation for the removal of methanol. In the first part, enzyme kinetics are elucidated for the solventless transesterification of two monoterpene alcohols with methyl acetate catalyzed by Novozym 435. Nonlinear regression revealed that three parameters (enzyme loading, forward and backward second-order reaction rate) sufficed to describe the entire conversion as a function of time. In the second part, a mathematical model for acetate ester production, integrated with organic–organic pervaporation, was developed based on a set of ordinary differential equations. To this end, empirical formulae for the pervaporation performance (of a PERVAP 2255-30 membrane and a standard HybSi® membrane) were established, relating methyl acetate and methanol flux to the methanol concentration in the reactor. The resulting digital twin, “PervApp”, allows us to study the influence of the key design parameters “enzyme loading” and “membrane surface” on, e.g., catalyst productivity. Finally, a techno-economic assessment is made for an annual production of 100 tons of geranyl acetate. The described methodology allows producers to shift from laborious, expensive and often disappointing trial-and-error approaches to the rational design of such integrated units.

scholarly journals Modeling the Average and Instantaneous Friction Coefficient of a Disc Brake on the Basis of Bench Tests

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4766
Author(s):  
Wojciech Sawczuk ◽  
Armando Miguel Rilo Cañás ◽  
Dariusz Ulbrich ◽  
Jakub Kowalczyk
Keyword(s):  
Friction Coefficient ◽  
Regression Models ◽  
Design Parameters ◽  
Railway Vehicle ◽  
Brake Disc ◽  
Operational Parameters ◽  
International Union ◽  
Disc Surface ◽  
Disc Brakes ◽  
Multiple Regression Models

This article presents the results of tests conducted on the average and instantaneous friction coefficients of railway vehicle disc brakes. The tests were carried out independently of various states of wear on the friction linings and the brake disc. The requirements of the International Union of Railways (UIC) regarding the approval of brake linings for use were taken into account. Based on many years of research using a brake bench to test railway disc brakes, the authors developed multiple regression models for the average friction coefficient and fluctuations (tolerances) in the instantaneous friction coefficient and achieved 870 results. The models proposed three types of variables: the input braking parameters (speed, pressure, and mass to be braked), operational parameters (the wear on the friction linings and the brake disc), and design parameters (perforations in the form of holes on the disc surface). The above two models were validated on the basis of 384 brakes, and in subsequent stages a further evaluation was performed. The coefficients were determined to be, respectively, 0.99 for the model of the average friction coefficient and 0.71 for the model of tolerance (fluctuations) of the instantaneous friction coefficient.

Preliminary Design of Ship Lines by Mathematical Methods

1970 ◽  
Vol 14 (01) ◽  
pp. 52-65
Author(s):  
G. Kuiper
Keyword(s):  
Design Method ◽  
Design Stage ◽  
Design Parameters ◽  
Mathematical Representation ◽  
Preliminary Design ◽  
Mathematical Methods ◽  
Qualitative Design ◽  
Preliminary Design Stage

A description is given of a mathematical representation of the ship's hull. The ship form can be given by a number of parameters, which are connected with the usual design parameters of a lines plan. Some qualitative design parameters such as U-or V-shaped sections can be formulated numerically. A design method is given which does not need more information than available at the preliminary design stage. Some results and variations are presented.

scholarly journals Shaping the appearance of a long-range aircraft at the stage of developing a technical proposal

2020 ◽  
Vol 47 (3) ◽  
pp. 49-59
Author(s):  
A. A. Gorbunov ◽  
A. D. Pripadchev
Keyword(s):  
Long Range ◽  
Rational Design ◽  
Performance Criteria ◽  
Design Stage ◽  
Design Solution ◽  
Design Parameters ◽  
Preliminary Design ◽  
Efficiency Criterion ◽  
Rational Design Parameters ◽  
Preliminary Design Stage

Objective. The process of designing a long-range aircraft, in particular at the preliminary design stage, involves comparing and analyzing a large number of design alternatives with specified performance criteria. At the same time, the problem of choosing the composition of rational design parameters is solved, which is an actual problem of the preliminary design stage of a long-range aircraft. Methods. The developed method allows determining the vector of parameters that provides rational characteristics for a given efficiency criterion. In this regard, the authors propose to introduce a global efficiency criterion - the takeoff weight of the long-range aircraft, and the specific criteria are the aerodynamic quality in cruise and the value of fuel efficiency. Results. In this formulation of the design problem, it is necessary to solve several interrelated problems, some of which are formalized, while others do not yet have a mathematical construct and software that allows automating the process. A distinctive feature of the proposed approach to finding a rational design solution is the use of statistical analysis methods in combination with methods of high-precision mathematical modeling, software-implemented in a single information environment using the Fortran V and C++ languages. Conclusion. The proposed method for selecting the composition of rational design parameters allows forming the appearance and providing the specified characteristics for its component elements at the early stages and stages of designing the long-range aircraft.

scholarly journals Optimal Design and Design Parameter Sensitivity Analyses of an eVTOL PAV in the Conceptual Design Phase

2020 ◽  
Vol 10 (15) ◽  
pp. 5112 ◽  
Author(s):  
Bong-Sul Lee ◽  
Abera Tullu ◽  
Ho-Yon Hwang
Keyword(s):  
Conceptual Design ◽  
Design Method ◽  
High Sensitivity ◽  
Sensitivity Analyses ◽  
Design Stage ◽  
Design Parameters ◽  
P Value ◽  
Conceptual Design Phase ◽  
Optimization Study ◽  
Independent Design

An optimization study of an electric vertical takeoff and landing personal air vehicle (eVTOL PAV) was performed during the conceptual design stage using the design of experiments method. In defining the initial problem, a design target parameter was set. The PAV subsystem was based on a configuration tradeoff study matrix, which was used to effectively conduct configuration selection. Initial sizing was performed using the PAV sizing program developed by this research team using Microsoft Excel and Visual Basic for Application (VBA). A screening test was performed to find parameters with high sensitivity among independent design parameters. The response surface method was used to model design target parameters, and a regression equation was estimated using the experimental design method. A Monte Carlo simulation was performed to confirm the feasibility of the generated model. To optimize the design independent parameter, a satisfaction function was selected, and the appropriateness of the data was determined using a Pareto plot and p-value.

scholarly journals A New Reliable Operating Region Design Method

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yue Chen ◽  
Jian Shi ◽  
Xiao-jian Yi
Keyword(s):  
Design Space ◽  
Design Method ◽  
Design Stage ◽  
Design Parameters ◽  
Maximum Volume ◽  
Numerical Examples ◽  
Operating Region ◽  
Convenient Approach ◽  
Axis Parallel ◽  
Target Performance

The reliable operating region, which is the set of all possible points in the design space that satisfy the reliability requirement, is capable to improve the reliability of products in the design stage. However, the reliable operating region has an irregular geometry shape and it is hard to derive an explicit expression; therefore, its practicality is poor. In order to obtain a more convenient approach, this paper proposes a reliable hyperrectangle operating region, which is expressed by permissible intervals for each design parameter and has the advantage that design parameters are decoupled. An iterative algorithm that seeks an axis-parallel reliable hyperrectangle with maximum volume is proposed. Starting from a design point with target performance, the lengths of the sides of the reliable hyperrectangle are iteratively updated. Theoretical analysis shows that the proposed algorithm is convergent. Furthermore, we extend the proposed methodology to deal with design space constraints. Some numerical examples and engineering cases demonstrate that the proposed algorithm can achieve the requirement of reliability efficiently.

scholarly journals Novel Methodology for Sizing a Single U-Tube Ground Heat Exchanger Useful at the Early Design Stage

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 651
Author(s):  
Seung-Hyo Baek ◽  
Byung-Hee Lee ◽  
Myoung-Souk Yeo
Keyword(s):  
Heat Exchanger ◽  
Energy Efficient ◽  
Design Method ◽  
Energy System ◽  
Design Stage ◽  
Design Parameters ◽  
Successful Implementation ◽  
Ground Heat Exchanger ◽  
Early Design ◽  
Early Design Stage

Renewable energy system (RES) is an environmentally friendly source of energy. A suitable design of RES is crucial to implement an energy-efficient building such as a zero energy building (ZEB). The significance of appropriate decision-making for the successful implementation of energy-efficient buildings has been increasing. In addition, the identification of the sizing of RES is equally important for architects or HVAC engineers. In this study, a novel sizing method for a single U-tube ground heat exchanger (GHE) is proposed. A transient thermal analysis for a single GHE is performed by considering ground temperature recovery effect as well as other major design parameters. The results are used to design the proposed sizing method and were verified by transient simulations for different design cases. Additionally, it was observed that the coefficient of variation of root mean square error (CV(RMSE)) for all ten design cases was lower than 15% during the heating and cooling seasons. Thus, the proposed design method can be used for sizing a GHE in the early design stage.

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