FEASIBILITY ANALYSIS OF LIQUID PROPELLANT SETTLING IN THE TANKS OF A SPACE PROPULSION SYSTEM AFTER FLYING IN ZERO GRAVITY USING A SEPARATING TURN MANUEVER OF THE ORBITAL UNIT

The paper presents results of preliminary design feasibility studies of using inertial settling of liquid propellant in tanks of space liquid rocket propulsion systems and separating from the propellant the ullage gases formed in zero gravity by means of centrifugal forces generated when the orbital unit performs the programmed turn maneuver proposed by the author. It shows that performing propellant settling and ullage gas separation by means of the separating turn maneuver makes it possible to significantly reduce propellant consumption in propulsion systems for attitude control and ullage engines. Key words: space liquid rocket propulsion system, main engine, separation of ullage gases from liquid propellant, separating turn maneuver of the orbital unit.

Feasibility analysis of liquid propellant settling in the tanks of a space propulsion system after flying in zero gravity using a separating turn maneuver of the orbital unit

The paper presents results of preliminary design feasibility studies of using inertial settling of liquid propellant in tanks of space liquid rocket propulsion systems and separating from the propellant the ullage gases formed in zero gravity by means of centrifugal forces generated when the orbital unit performs the programmed turn maneuver proposed by the author. It shows that performing propellant settling and ullage gas separation by means of the separating turn maneuver makes it possible to significantly reduce propellant consumption in propulsion systems for attitude control and ullage engines. Key words: space liquid rocket propulsion system, main engine, separation of ullage gases from liquid propellant, separating turn maneuver of the orbital unit.

Features of the system approach to safety stand tests of liquid rocket propulsion systems

Пояснена необходимость разработки и реализации специальных мероприятий при применении системного подхода к безопасности стендовых испытаний двигательных установок ракет. Определена основная концепция промышленной безопасности при стендовых испытаниях кислородно-водородных двигательных установок. Изложено и обосновано содержание специальных мероприятий по безопасности испытаний. Предложена функциональная модель безаварийного проведения испытаний и определены мероприятия для её эффективного применения. It explains the need to develop and implement special measures for a systematic aproach to the safety of stand tests of rocket propulsion systems. The basic concept of industrial safety during stand tests of oxygen-hydrogen propulsion systems is defined. The content of special measures for test safety is described and justified. A functional model of trouble-free testing is proposed and measures for effective application are defined.

Study of Manufacturing Processes for Liquid Rocket Turbopump Impellers: Test and Analysis

In the context of the cooperative development of the L75 Liquid Rocket Engine (with 75 kN of thrust) and in the frame of a global enlargement of competence in the field of turbomachines for liquid rocket propulsion systems, Institute of Space Propulsion of the German Aerospace Center (DLR; in German, Deutsches Zentrum für Luft- und Raumfahrt), in Lampoldshausen, and the Brazilian Institute of Aeronautics and Space (IAE; in Portuguese, Instituto de Aeronáutica e Espaço) have managed to produce its first flight ready components for pumps in liquid rocket propulsion systems. Among these components was a series of prototyped shrouded impellers for the oxidizer pumps manufactured in different materials and by different fabrication processes executed by four independent Brazilian and German workshops. Non-destructive and destructive testing methods have been applied for impellers materials validation, and for manufacturing processes verification. A special attention was given to the spin tests results and analysis, which included verification at maximum operational speed and burst testing, in order to determine the failure speed. Each tested impeller reached the required specification for the application in the L75 turbopump. Spin test logic and test results are discussed later on. Therefore, the scope of the present study is to investigate several traditional and cutting-edge processes applied for shrouded turbopump impellers manufacturing. A verification and validation of these processes will also be discussed.

Experimental estimation of residual propellant in the fuel tanks with innertank capillary devices for spacecraft propulsion systems

The paper presents the results of experimental studies of the processes of emptying the fuel tanks of spacecraft liquid rocket propulsion systems at the final stages of free (undisturbed) flight in tanks with innertank capillary devices (IT CD). On the basis of the analysis of the emptying process, the dimensionless complex structure is formed. The complexes determine the dependence of the residual propellant on the physical properties of the propellant and the parameters of the IT CD. Experimental studies were performed on the weightlessness stand, using the principle of realization of the conditions of reduced weight in tested equipment free fall. The results of the experimental studies have shown that the main criterion determining the value of residual propellant is the Froude number. The criterion equation for determination of residual propellant is obtained. The influence of viscosity and surface tension of the propellant on the value of residual propellant begins to affect at the values of the Froude numbers exceeding 104.