Defining the rational installation position for the discharging unit of the bucketless rotary imple-ment in the trenching excavator

The increasing volumes of the earthworks performed by trenching excavators during the creation of the lengthy excavations in the soil for the pipelines of different sizes and other purposes create the need to improve the excavators, to create new highly productive machines of the fundamentally new construction. The goal of this work is to increase the performance of trenching excavators equipped with the bucketless rotary implement by improving the process of the soil discharging from the implement. To achieve this goal it is required to reveal the physical essence of the soil excavation by the bucketless rotary implement and based on the performed study to determine the rational installation position for the discharging unit of the bucketless rotor. Methodology. The scientific hypothesis is that discharging of the inner circular cavities of the bucketless rotor during the trench digging and the movement of the excavated soil to the side from the trench is possible by means of rational use of the flow header pressure of the soil that is being transported in the rotor from the excavation. The study is performed with analytical methods using basic principles of the theoretical mechanics, flowing medium statics, force analysis. Results. The study confirms the scientific hypothesis of the possibility to discharge the bucketless rotary implements of the trenching excavators by using the flow header pressure of the excavated soil that is transported by the rotor from the excavation, rational installation position of the discharging unit of the implement is defined. Originality. The scientific novelty of the study lays in the rationale and confirmation of the possi-bility to excavate and transport the soil from the excavation with the implements of the rotary trenching excavators with continuous flow and not with the separate portions. Practical value. Practical value lays in ensuring the 2-5 times performance increase of the excavation using the bucketless rotary implements.

Development of a device for determining the coefficient of adhesion of a tire simulator with a flat support surface

To ensure optimal braking performance, i.e. minimum braking distance while maintaining the stability of the car at the limit of controllability, anti-lock systems are currently installed on cars. The relative fraction of the rest friction in the contact spot, which is used to form the longitudinal reaction of the support surface at the appropriate value of the slip coefficient, in relation to the total fraction of the rest friction in the contact spot is a constant value for any type and condition of the road surface. The coefficient of adhesion in physical essence is the coefficient of friction at rest. The proposed device for determining the coefficient of adhesion of a tire simulator with a flat horizontal support surface will simplify the design and increase the measurement accuracy. Keywords: coefficient of adhesion, a device for determining the coefficient of adhesion, a device

Atomic mapping of periodic dipole waves in ferroelectric oxide

A dipole wave is composed of head-to-tail connected electric dipoles in the form of sine function. Potential applications in information carrying, transporting, and processing are expected, and logic circuits based on nonlinear wave interaction are promising for dipole waves. Although similar spin waves are well known in ferromagnetic materials for their roles in some physical essence, electric dipole wave behavior and even its existence in ferroelectric materials are still elusive. Here, we observe the atomic morphology of large-scale dipole waves in PbTiO3/SrTiO3 superlattice mediated by tensile epitaxial strains on scandate substrates. The dipole waves can be expressed in the formula of y = Asin (2πx/L) + y0, where the wave amplitude (A) and wavelength (L) correspond to 1.5 and 6.6 nm, respectively. This study suggests that by engineering strain at the nanoscale, it should be possible to fabricate unknown polar textures, which could facilitate the development of nanoscale ferroelectric devices.

Use of the kinematic radius in the rolling mechanics of an elastic wheel

The analysis of the physical essence of the kinematic and dynamic radii of the wheel is given. It is stated that the rolling radius of the wheel is a conditional kinematic parameter that characterizes only the rolling mode of the wheel. It is not the shoulder of all longitudinal forces acting on the wheel and should not be used to determine tractive forces, rolling resistance and wheel braking forces. Specific examples are given to illustrate the inappropriateness of using the kinematic radius to determine forces and moments. Keywords: elastic wheel, rolling radius, kinematic radius, dynamic radius, arm of force, traction force, rolling resistance force, braking force, rolling mode

The Concept of space-time quanta in future technologies

The article discusses the possibility of using the technological advantages that appear in connection with the discovery of the physical essence of Time and new interpretation of the structure of space in the form of space-time quanta. One of the problems that can be successfully solved on the basis of the new physical model is the problem of establishing the true nature of gravity. The solution to this problem is directly related to the implementation of the idea of unsupported motion based on the interaction in a certain way of the created asymmetric interference structure of longitudinal waves with the natural structure of spatial frequencies.

Prediction of Rotor Burst Using Strain-Based Fracture Criteria to Comply with the Engine Airworthiness Regulation

Relative to the rotor overspeed compliance governed by civil aviation airworthiness regulation, nowadays Area-Average Stress method is commonly used approach. However, in order to effectively apply the Area-Average Stress method in analyzing burst speed, large amount of testing data is needed to define an important element of this method: a correction factor. This prerequisite hinders the use of this method for many companies which have limited test data. Meanwhile, analysis of rotor burst speed based on Strain-based Fracture Criteria using true stress-strain curves and burst tests has been done on the LPT rotor, and a work procedure obtaining the most critical burst speed for certification is proposed. The analysis results, which had a good correlation with test results, showed that Strain-based Fracture Criteria can accurately predict the burst speed considering the most adverse combination of dimensional tolerances, temperature, and material properties, and rotor dimensional growth under the overspeed condition. Both are required by the aircraft engine airworthiness overspeed regulation. Compared to the Area-Average Stress method, Strain-based Fracture Criteria reflects the physical essence of the rotor burst more realistically and can be simply verified without requiring too much test data, therefore it has a good application prospect in the aircraft engine airworthiness.

Hydraulic resistances of derivation channels of hydropower facilities

Currently, many authors have studied the uniform axisymmetric pressure head laminar and turbulent movement of water in hydraulic smooth and rough (with uniform roughness) pipes of circular cross-section. The results obtained in the study of a plane-parallel turbulent flow in pressure channels allow here only to outline the structure of the corresponding dependencies and to clarify the simplest case of unpressurized fluid movement, when this movement can also be reduced to plane-parallel or, in other words, to movement in channel of infinitely large width with a flat bottom. In all other cases, the only way to solve the problem is experiment. But the possibilities of the experiment are limited, as are limited, and in a number of cases debatable, and the information accumulated to date on the uniform free-flow motion of fluid in channels of various cross-sectional shapes. The unpressurized uniform movement of fluid in channels of various cross-sectional shapes has been completely insufficiently studied. The construction of numerous free-flow watercourses, as well as machine channels of pumping stations, requires scientifically based calculation methods. For the correct establishment of hydraulic calculation methods, a sufficiently deep study of the physical essence of the phenomena occurring in the free-flow derivation channels is necessary. The extensive construction of numerous free-flow watercourses, as well as hydroelectric power plant (HPP) derivation channels, requires scientifically based calculation methods. For the correct establishment of hydraulic calculation methods, a sufficiently deep study of the physical essence of the hydraulic phenomena occurring in the free-flow derivation channels of HPPs is necessary.

The Concept of space-time quanta in future technologies

The article discusses the possibility of using the technological advantages that appear in connection with the discovery of the physical essence of Time and new interpretation of the structure of space in the form of space-time quanta. One of the problems that can be successfully solved on the basis of the new physical model is the problem of establishing the true nature of gravity. The solution to this problem is directly related to the implementation of the idea of unsupported motion based on the interaction in a certain way of the created asymmetric interference structure of longitudinal waves with the natural structure of spatial frequencies.

RELATIVE PRINCIPLE OF FULL ABSORPTION

The paper discusses the principle of complete absorption, which plays the same role in relational theory as the principle of equivalence in general relativity and the principle of waveparticle duality in quantum theory. The physical essence of this principle boils down to the fact that a sufficiently large number of particles must be present in the Universe so that complete absorption of radiation from any source is possible. This implies complete equivalence, from the experimental point of view, of direct interparticle interaction and the interaction carried by a local field in spacetime. It is noted that in its classical interpretation the Fokker variational principle, on which the theory of direct interparticle interaction is based, contains a dilemma caused by two mutually contradictory necessary properties of the interaction action. One of the options for overcoming this dilemma is proposed.