Annotation: The paper presents the experiment-calculated data on hydraulic parameters of ring intake device in different operation modes. The method of their calculation is proposed taking into account limit deviations of influencing factors. Satisfactory convergence of calculated and experiment data is shown.

Annotation: The effective documents in the field of metrological support require evaluating measurement uncertainty during measuring instrumentation calibration. In Ukraine, there is no regulated procedure of uncertainty calculation during measuring instrumentation calibration, which causes the necessity of developing such procedure. This article proposes the measurement uncertainty calculation procedure during measuring instrumentation calibration, according to which the following calculations shall be made: a) of standard uncertainty of A type for corrected observation results obtained during calibration; b) of standard uncertainties of B type caused by error or uncertainty of working standard applied, calculation discreteness or calibrated measuring instrument division value, variation of calibrated measuring instrument indications; c) of total standard measurement uncertainty; d) of augmented measurement uncertainty. As an example, the results of calculation of augmented measurement uncertainty during calibration are presented: – for 795M107B vibrometer in complete set with AC102-1A accelerometer; – for alternating voltage measurement channel of a measuring and computing complex of MIC type; – for a manometer of MT type. The obtained results of measurement uncertainty calculation are presented in the form of tables of measurement uncertainty budget, which shall be entered in the measuring instrument calibration certificate together with the observation results obtained during calibration. The proposed uncertainty calculation procedure is applicable for the given types of measuring instruments whose calibration is performed by method of direct measurement of known measurement values represented or controlled by working standards.

Annotation: The paper presents a complex of analytical calculation measures that allow increasing tanks useful volume and ensure engines’ additional operational lifetime by the example of a launch vehicle, one of Yuzhnoye SDO developments. The calculated-experimental confirmation is set forth of the operability of pneumohydraulic supply system in the changed conditions that ensure considerable increase of launch vehicle power and mass characteristics.

Annotation: The analysis is presented of measurement uncertainties components by A and B types during metrological certification of measuring instrumentation. The example is presented of the evaluation of measurement uncertainties of pressure measurement channel. Introduction of the methodology under consideration will ensure compliance of the metrological characteristics determined with the regulations of international normative documents.

Annotation: Long-term experience in development, development testing and use of generating systems of fuel tanks pressurization for rockets powered by nitrogen tetroxide and unsymmetrical dimethylhydrazine is summarized. Replacement of gas bottle pressurization systems with generating ones on such launch vehicles as 15A14, 15A15, 11K68 (8K67), 15A18M substantially simplified operation, reduced the pneumohydraulic feed system mass at least twice and its cost – by five times. Typical stages of development and introduction of the pressurization generating systems are shown: development of generators, their development testing, study of the composition and parameters of gas. The important steps were the development of methodology for pressurization system parameters calculation, which enabled achievement of the substantial improvements of their characteristics, appearance of the high-performance hightemperature (up to ~ 1000o C) unsymmetrical dimethylhydrazine tank pressurization system, study of the degree of impact of each of the pressurization system parameters on the tank pressure. Accounting of the correlation between the flow rate and the generator gas temperature improved the output performance, as well as simplified and reduced the amount of development testing of the pressurization system. Important role of the gas sprayer design in pressurization system parametric configuration is described, and the advanced versions are shown taking into account g-loads, changes in temperature, pressure and propellant level inside the tank. Significant phase in the development of the generating pressurization system was the effective use of the high-temperature pressurization of the fuel tank with submerged propulsion system. Besides for the first time the effect of mechanical temperature destratification of the propellant in the tanks was observed, which occurs during the propulsion systems shutdown. Due to this effect, the Dnepr LV payload capability enhanced. Successful engineering solutions in the design of the pressurization system were defended by ~80 copyright certificates and patents of invention, ~40 of which were successfully implemented.

Annotation: Applicable documents on metrological assurance regulate the estimation of measurement uncertainty. In Ukraine there is no regulative methodology for uncertainty calculation when certificating test equipment that causes the necessity of its definition. This article offers the methodology for uncertainty calculation when certificating a centrifugal machine that is used to reproduce precisely the given value of linear acceleration that permanently acts on a tested unit spinning together with a rotor. The offered methodology for uncertainty calculation is applicable to centrifugal machines, for which numerical values of reproducible linear acceleration are determined by results of calculations of the centrifugal machine’s rotor angular velocity and radial distance from rotor’s longitudinal axis to the given point of the tested unit. Initial data used were results of observation obtained after multiple reproductions of the given values of linear acceleration as well as numerical values of errors and measurement uncertainties of measuring equipment that was used when monitoring the rotary angular velocity and radial distance considering the contribution of each measurable parameter to a certain value of linear acceleration. The calculation given in the article estimates the limit of linear accelerations that can be attributed with established probability to the given value of linear acceleration reproduced when certificating the centrifugal machine. The design formulae are given to estimate the uncertainty components of the reproducible values of linear accelerations and the recommendations are given to present the uncertainty budget.

Annotation: The main task of the radiotransparent radome design is to develop a structure that reliably protects the aircraft components, sensitive instrumentation of the guidance system from incoming air flow and heating in all phases of operation, meeting all the requirements of minimum weight, allowable temperature under the radome, strength, centre of mass and radio characteristics. Development of the radome solves the complex task of coupling and optimization of the geometric aspects of design with physical-mechanical, radio and thermal properties of materials. The article dwells on the aspects of development of the radiotransparent radomes depending on the aircraft flight speed; basic requirements for the selection of outside perimeter configuration; structural materials, providing the required radio properties in combination with minimum mass and necessary strength, acceptable temperature inside the fairing. Yuzhnoye-developed radome for the up to 5 M aircraft was considered, consisting of ogive shell made of АФ-10ПО fiberglass, heat-resistant tip and structural ring made of aluminum alloy. Methods of thermal and strength analyses of the shell are considered, results of calculations confirming the fitness for work of the structure are presented. Options of configuration with ceramic shells and methods of their coupling with rings are presented for the aircraft that reaches up to 5 M speed. Basic principles of radiotransparent radomes development and aspects of ceramic shells coupling with structural rings are considered, as well as the results of strength analyses and thermal calculations that ensure the performance of the structure and equipment in the area under the radome.

Annotation: The solid rocket motors thrust is measured according to the developed measurement procedure; fulfilment of its requirements guarantees obtaining the results with required accuracy parameters. Compliance of this procedure with the measurement accuracy requirements is confirmed by way of its validation that can be performed according to different algorithms. The proposed article deals with two validation algorithms of measurement procedure for solid rocket motor thrust up to 30 tf – end-to-end and link-by-link validation methods. The composition of measurement channel, the experimental works performed at each validation algorithm are described, the calculation formulas to evaluate the limits of absolute measurement error and the obtained numerical values of the latter are presented. The comparative analysis of the results of validation procedure of solid rocket motor thrust measurement procedure obtained during metrological investigations of thrust measurement channel by end-to-end and link-by-link validation methods shows that to ensure the required measurement accuracy, the algorithms of end-to-end method is preferable, at which the lower values of reduced error can be obtained as compared with the algorithm of link-by-link validation.

Annotation: One of the systems in the integrated launch vehicle responsible for prelaunch processing and launch is a ground thermal conditioning system, which supplies the low-pressure air into the launch vehicle’s “dry” compartments. Thermal conditioning system is mated with the launch vehicle, using the mating interfaces, proper functioning of which enhances reliability of the ground support equipment, the launch vehicle and the entire space launch system. The article describes key requirements to the interfaces of the thermal conditioning system and the drawbacks of the existing designs. The article proposes a new design concept of the interface that connects the pipeline of the ground thermal conditioning system to the orifice of the launch vehicle using the corrugated rubber hose composed of three basic parts, attached with the help of a metal lock/release assembly. The proposed solution provides reliable leaktightness, ease of operation, providing multiple connections to the launch vehicle, including at various angles, and automatic disconnection by rocket motion or manual removal in case of launch abort. Using rubber as a high-elasticity structural material to manufacture the hoses, enabled minimization of efforts required to disconnect the interface from the launch vehicle. In its high-elasticity state, rubber can absorb and dissipate mechanical energy within a wide range of temperatures, which prevents transmission of engine vibrations to the ground thermal conditioning system. The article presents key properties of rubber used as a structural material and its peculiarities to be considered during design of similar products. Unlike metal showing two types of deformation (elastic and plastic), rubber can exhibit three types of deformation (elastic, superelastic and plastic). In the process of interface design, we took into account two types of deformations (elastic and superelastic ones). Experimental studies of the interface showed its full compliance with technical specification.