Autor: Ułanowicz, L. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Outline of the method for prediction of lifetime achieved by ayionic hydraulic drives operated under real field conditions
Autorzy:: Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/242145.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: lifetime
probability density function
hydraulic drive
pump delivery
structural parameter
deterioration rate
wear and tear
Opis:: The presented approach to predict lifetime of avionic hydraulic drives belongs to a priori (accelerated) methods as by its nature it does not reeuire to continue tests until a hydraulic subassembly or drive reaches its boundary value of a structural parameter. The method uses distributions of a random variable with time-dependent variance as models for lifetime prediction. Variations of structural parameters over a discretional period of time are described with use of the Gaussian distribution with the assumption that the course of the process when the structural parameters are subject to deterioration comprises the entire probabilistic characteristic that defines resistance of the hydraulic drive to a wear and tear process. In that context distributions of characteristics for variations of structural parameters were determined for a selected period of time and it served as a basis to find out parameters for the distribution of the defect-free operation time. The completed functional and design decomposition of an example avionic hydraulic drive made it possible to obtain a hierarchical description of the hydraulic drive, to identify its structural parameters that are available during the drive operation as well as to define a set of measurable out put parameters of a system, a module (a hydraulic system) and a block (a hydraulic subassembly). The set of measurable output parameters attributable to the hydraulic system in question is described with use of mathematic equations that result from fundamental equations for hydraulic systems dynamics, i.e. the mass conservation law, the principle of momentum and angular momentum conservation as well as the energy conservation law.
Źródło:: Journal of KONES; 2009, 16, 2; 473-484
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Wear processes in precise pairs of hydraulic control devices
Autorzy:: Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/244215.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: aviation
hydraulic drive
hydraulic precise pair
wear by oxidation
adhesive seizing
tacking
Opis:: One of the most important tasks in a complex of activities aimed at increasing the use quality of a hydraulic drive are studies concerning the impact of operating conditions of hydraulic precise pairs on their durability. With supercritical values of the slide velocity, there is a stepwise and rapid quantitative characteristics of the wear process on the surface of a hydraulic precise pair’s elements. The phenomenon of wear by oxidation and the occurrence of adhesive seizing (tacking), created in the course of the process of mutual impact of surfaces of hydraulic precise pairs in control devices, under load resulting from a hydraulic drive’s pressure pulsation requires thorough consideration. The paper discusses operating conditions of slider pairs of hydraulic control devices associated with the kinetics of their movement and their load conditions. They were supported by results of empirical studies. General characteristics and mechanism of the wear by oxidation in a slider control pair was presented. The impact of loss of stability of a control spring in a slider control pair and the relative displacement of pair’s elements during the operating process, on the character and intensity of the adhesive seizing event were discussed. The conditions of occurrence of adhesive seizing in hydraulic slider pairs, under load resulting from pressure pulsation in a hydraulic drive were discussed.
Źródło:: Journal of KONES; 2016, 23, 1; 405-412
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Outline of a model for flow of inhomogeneous working fluids via an interstice
Autorzy:: Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/245561.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: interstice
positive allowanc
manifold plunger (spool)
flow rate
volumetric content of contaminations
filtration
contamination concentration
Opis:: The paper presets flow characteristics of a hydraulic unit made up of a cylinder and a plunger, which is typical for most of precision pairs, as a function of contamination content in the working fluid. The consideration cover typical cases, including flow of contaminated fluid via an interstice (positive allowance), when the manifold plunger (spool) is in its initial position and the flow rate Qz of the working fluid at the manifold inlet is higher than the flow rate Q via the interstice, the manifold plunger (spool) is in its initial position and the flow rate Qz of the working fluid at the manifold inlet is lower than the flow rate Q via the interstice and when the manifold plunger moves against the manifold cylinder (body). Mathematical relationships, determined for all the above cases, define the following characteristics: volume of contaminants captured upstream the interstice, volume of contaminants captured in the interstice, volume of contaminants that flow out downstream the interstice, flow rate of the working flow downstream the interstice as a function of time, average velocity for the working fluid that flows out of the interstice as well as time interval that is necessary to fill in the interstice. Distribution of contaminants along the interstice length is described as well. The determined relationships served as a basis to find out interconnections between volumes of fluid that flows via an interstice and duration of the flow process.
Źródło:: Journal of KONES; 2009, 16, 3; 471-482
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: Wear processes of hydraulic plunger and barrel assemblies connected with the time of their work
Autorzy:: Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/246273.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: fluid power transmission
pump delivery
volume flow rate
hydraulic precision pair
avionic technology
Opis:: The article discusses the wear processes of hydraulic plunger assemblies connected with the time of their work and the impact exerted by these processes on the value of parameters of a hydraulic plunger pump. It describes working conditions and loading of a hydraulic plunger assembly. The paper presents also the results of empirical analyses of the wear process of the connection of the plunger base with the working surface of the swivel disk, which is related to time and conditions of its work. It discusses the impact of the loading value and sliding speed on the character and intensity of the wear of the connection between the plunger base and the working surface of a swivel disk. Furthermore, it presents a general characteristic and mechanism responsible for the wear of the hydraulic plunger assembly through oxidation. The article also analyses the impact of the hardness of materials used for producing the hydraulic plunger assembly on the intensity of its wear. Another issue is the dependence of the coefficient of friction in the hydraulic plunger assembly on the contact pressure at different sliding speeds. Finally, the paper discusses the impact of wearing of the cooperating plunger base and the working surface of the swivel disk on the initial parameters of the hydraulic pump at a given working pressure and its volumetric efficiency.
Źródło:: Journal of KONES; 2014, 21, 4; 515-524
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Effect of dynamic properties attributable to hydraulic lines onto operation of avionic
Autorzy:: Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/247057.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: fluid power transmission
pump delivery
volume flow rate
hydrostatic (forcing) pressure
compressibility effect
viscous friction effect
Opis:: The present paper is dedicated to discuss how dynamic parameters of a hydraulic line intended to transfer hydraulic power from a source of hydraulic power (a hydraulic pump) to an actuating device (a hydraulic motor) can affect operation of an avionic hydraulic drive. Avionic hydraulic drives are operated with fast-varying waveforms of flow intensities and pressures. It is why analysis of most hydraulic drive systems must take account of compressibility of working fluid and elasticity of hydraulic lines. It leads to a wave model for propagation of energy variation down a hydraulic line (a pipe). The paper deals with flow of a compressible liquid via a hydraulic line with flexible walls. Theoretical deliberations were successfully verified by experimental research studies that were carried out on a dedicated test bench, therefore the presented amplitude vs. frequency characteristic curves of the hydraulic line could be obtained from both theoretical considerations and experimental research studied. The experimental research studies were carried out for hydraulic line terminated with a fixed flow restrictor alone and a flow restrictor combined with a hydraulic accumulator as well as for a hydraulic line supplied from a source of constant pressure and terminated with a valve with adjustable flow together with a hydraulic accumulator. The theoretical calculations for the amplitude vs. frequency characteristic curve are based on a model for a hydraulic line with its resistance depending on frequency.
Źródło:: Journal of KONES; 2011, 18, 4; 535-542
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 6.

Tytuł:: Analysis of dynamic properties of hydraulic lines for fluid power transmission
Autorzy:: Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/247615.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: fluid power transmission
delivery of a pump
volume flow rate
hydrostatic (forcing) pressure
compressibility effect
viscous friction effect
Opis:: This paper presents the results of a hydraulic line dynamic properties analysis taking into account inertia of the fluid flowing in rigid and flexible lines, the compressibility effect for this fluid and the viscous friction effect. The following are described and analyzed: solution of the wave equation in the form binding four variables: pressure and flow rate at the line input, and pressure and flow rate and the line output; two of the above-mentioned variables should be regarded as independent (input) and the other two as dependent (output), the accuracy comparison of distributed parameters model to lumped parameters model with regard to applicability range in hydraulic systems analysis, pressure value at given installation points as a response to rapid valve closing (transient response) or to valve opening (waterhammer effect). In these considerations the hydraulic line is regarded as a two-port with two inputs and two outputs with a definite transmittance matrix. Main considerations concern the variable resistance model. A general solution is given as a function of the Laplace operator. Introducing appropriate simplifications into the variable resistance model, the constant resistance model and lossless line model is obtained. Also, general solutions for three different lump parameter models are presented. For the lumped parameters lin presents three equivalent models possible, i.e. as: a symmetrical two-port, a two-port with shared resistance and a two-port with capacitance at the output.
Źródło:: Journal of KONES; 2010, 17, 3; 467-475
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 7.

Tytuł:: Modelling of a process, which causes adhesive seizing (tacking) in precise pairs of hydraulic control devices
Modelowanie procesu wywołującego zacieranie adhezyjne (sczepianie) w parach precyzyjnych hydraulicznych urządzeń regulacyjnych
Autorzy:: Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/1365738.pdf
Data publikacji:: 2016
Wydawca:: Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:: aviation
hydraulic drive
hydraulic precise pair
adhesive seizing
tacking
lotnictwo
napęd hydrauliczny
hydrauliczna para precyzyjna
zacieranie adhezyjne
sczepianie
Opis:: Lack of complete knowledge in the scope of the impact of operating conditions of precise pairs of hydraulic units on the character of the destructive processes arising in them, results in not taking these conditions into account at the early stages of design and manufacturing. One of such little described issues are factors causing adhesive seizing (tacking), created during the process of interaction between slider surfaces of pairs of hydraulic control devices under contact-vibration load. The articles presents general characteristics and mechanisms causing adhesive seizing (tacking) in precise pairs of hydraulic control devices under contactvibration load. It also presents a model describing the process, which causes adhesive seizing (tacking) in a slider hydraulic pair under contact-vibration load. The model allows to carry out both, qualitative, as well as quantitative analysis of the impact of vibration and load parameters on the occurrence of adhesive seizing (tacking) in slider pairs of hydraulic control devices. Practical application of the model requires the determination of the values of coefficients, which characterise the intensity of restoration and seizing resistance of metal oxides on cooperating surfaces of a hydraulic pair. An empirical method for estimating coefficients of the model and an example of estimating model coefficients for a pressure increase limiter were presented.
Brak pełnej wiedzy w zakresie wpływu warunków pracy par precyzyjnych zespołów hydraulicznych na charakter powstawania w nich procesów destrukcyjnych powoduje, że na etapach projektowania i wytwarzania nie uwzględnia się tych warunków. Jednym z takich mało opisanych zagadnień są czynniki wywołujące zacieranie adhezyjne (sczepianie), powstające w procesie wzajemnego oddziaływania powierzchni suwakowych par hydraulicznych urządzeń regulacyjnych przy obciążeniu kontaktowo-wibracyjnym. W artykule przedstawiono ogólną charakterystykę i mechanizmy wywołujące zacieranie adhezyjne (sczepianie) w hydraulicznych parach precyzyjnych urządzeń regulacyjnych przy obciążeniu kontaktowo-wibracyjnym. Zaprezentowano model opisujący proces wywołujący zacieranie adhezyjne w suwakowej parze hydraulicznej przy jej obciążeniu kontaktowo – wibracyjnym. Model pozwala przeprowadzić zarówno jakościową, jak i ilościową analizę wpływu parametrów wibracji i obciążenia na wystąpienie zacierania adhezyjnego (sczepiania) w suwakowych parach hydraulicznych urządzeń regulacyjnych. Praktyczne wykorzystanie modelu wymaga określenia wartości współczynników charakteryzujących intensywność odtwarzania i opór ścierania tlenków metalu ze współpracujących powierzchni pary hydraulicznej. Przedstawiono empiryczną metodę szacowania współczynników modelu i przykład szacowania współczynników modelu dla ogranicznika narastania ciśnienia.
Źródło:: Eksploatacja i Niezawodność; 2016, 18, 4; 492-500
1507-2711
Pojawia się w:: Eksploatacja i Niezawodność
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 8.

Tytuł:: Experimental method of determining characteristics of power and torque engine for low-power unmanned aerial vehicles
Autorzy:: Jastrzębski, G.
Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/245545.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
internal combustion engines
motor test
motor braking
Opis:: The article presents an analytical determination of power and torque of internal combustion engines of small power. It measured actual power and torque characteristics of internal combustion engines of small power. Three types (methods), braking (receiving power via a hydraulic pump, generator and a package of propellers with variable angle of attack. For each method of receiving power (braking) determined the characteristics of torque and power. There is the summary of results for one engine with different ways of braking. There have been evaluation of the presented methods inhibit combustion piston engines of small power as methods for determining power internal combustion engines. The analysis methods presented in the perspective of the braking engine selection for light unmanned aircraft, and the use of parameters derived from research into engine control. Subject to the evaluation method of adjustment (increase) charged, increasing the load on a liquid or ankle. The criterion for comparing methods for inhibition of internal combustion engines of small power load assumed dependence on the rotational speed n, and obtain maximum power on the motor shaft when the throttle, a reflection of the actual engine operating parameters in its target applications.
Źródło:: Journal of KONES; 2011, 18, 3; 135-142
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 9.

Tytuł:: Methods for determining the take-off speed of launchers for unmanned aerial vehicles
Autorzy:: Jastrzębski, G.
Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/243050.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: aviation
unmanned aerial vehicle
take-off launcher
take-off speed
acceleration recorder
lotnictwo
bezzałogowy statek powietrzny
prędkość startu
rejestrator przyspieszenia
Opis:: Unmanned aerial vehicles (UAV) are currently a very rapidly developing type of aviation. The problem of support during the take-off with the use of, i.e. take-off launchers arose along with their development, especially for UAVs with weights and dimensions preventing manual take-off. One of the major issues associated with UAV take-off launchers is for its UAV accelerating element to obtain its initial speed. The article presents three methods of determining launcher take-off speeds for unmanned aerial vehicles, i.e. the concentrated very oblique projection method, the high-speed camera methods, and the acceleration recorder method. The take-off launcher carriage speed in the oblique projection method is determined from a formula. This method involves “ejections” of concentrated masses from the UAV mass range and measuring the component values resulting from the used formula, which contains the range of the oblique projection, the elevation of the projection and its angle. The method using the high-speed camera involves recording the course of ejections of the concentrated mass from the launcher. The average take-off speed is determined on the basis of a take-off run length (section of the launcher race, where the unit accelerates) and defining the start and end frame of the carriage movement. The third method for the determination of the take-off speed utilizes an acceleration recorder. The method with the recorder involves registering a change in the accelerations when the take-off carriage is being accelerated by a system fixed on the carriage or the accelerated object. The article presents the methodology of dynamic tests of object acceleration on a launcher, necessary for the determination of speed with the mentioned methods. Selected results from actual tests with the use of the 01/WS/2015 launcher, which is an element of the ZOCP JET2 set, were presented. The test results are presented in a tabular form. The methods for the determination of the take-off speed were compared on the basis of performed tests. Based on the obtained results, the factors impacting the accuracy of each of the methods were identified.
Źródło:: Journal of KONES; 2018, 25, 1; 170-176
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 10.

Tytuł:: The analysis of working liquid flow in a hydrostatic line with the use of frequency characteristics
Autorzy:: Ułanowicz, L.
Jastrzębski, G.
Powiązania:: https://bibliotekanauki.pl/articles/200309.pdf
Data publikacji:: 2020
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: aviation
unmanned aerial vehicle
hydrostatic drive
servomechanism
hydrostatic line
Opis:: One of the little described problems in hydrostatic drives is the fast changing runs in the hydraulic line of this drive affecting the nature of the formation and intensity of pressure pulsation and flow rate occurring in the drive. Pressure pulsation and flow rate are the cause ofthe unstable operation of servos, delays in the control system and other harmful phenomena. The article presents a flow model in a hydrostatic drive line based on fluid continuity equations (mass conservation), maintaining the amount of Navier-Stokes motion in the direction of flow (x axis), energy conservation (liquid state). The movement of liquids in a hydrostatic line is described by partial differential equations of the hyperbolic type, so modeling takes into account the wave phenomena occurring in the line. The in hydrostatic line was treated as a cross with two inputs and two outputs, characterized by a specific transmittance matrix. The product approximation was used to solve the wave equations. An example of the use of general equations is presented for the analysis of a miniaturized hydrostatic drive line fed from a constant pressure source and terminated by a servo mechanism.
Źródło:: Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 949-956
0239-7528
Pojawia się w:: Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Informacja

Wyszukujesz frazę "Ułanowicz, L." wg kryterium: Autor

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język