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Pressure regulator design for liquid propellant rocket engines

Pressure regulator design for liquid propellant rocket engines

##### Dosyalar

##### Tarih

2023-06-06

##### Yazarlar

İnanç, Çağrı

##### Süreli Yayın başlığı

##### Süreli Yayın ISSN

##### Cilt Başlığı

##### Yayınevi

Graduate School

##### Özet

Liquid propellant rocket engines (LPRE) are powerful and complex systems that play an important role in space exploration and flight technologies. These engines use a propellant pair, usually an oxidizer and a combustible propellant. The thrust obtained from the combustion reaction of these propellants, propels the rocket. Liquid propellant rocket engines have the advantages of high thrust, high efficiency and controllability. These engines are used in many application areas such as space exploration, satellite launches, deep space exploration and unmanned space missions. The design of these high-tech engines involves a series of complex engineering problems such as fuel supply, combustion control and cooling. Liquid propellant rocket engines are of great importance for the future of manned and unmanned space travel, and are becoming more efficient, reliable and powerful with continuously developed technologies. Flow control components in liquid propellant rocket engines are an important part that ensures correct and regular feeding of liquid propellants into the combustion chamber of the engine. These components ensure that the propellants are filled into the tanks, directed to the combustion chamber at an appropriate pressure and that the combustion reaction takes place in a stable manner. In addition, flow control components must be flexible and able to function safely to adapt to pressure and temperature changes in the combustion chamber. The design of these components requires precise engineering calculations and material selections to optimize the system, minimize energy losses and increase engine performance. Flow control components are a critical element for the reliability, efficiency and successful operation of liquid propellant rocket engines, and are made more effective and durable with constantly improved technologies. Pressure regulators are an essential component in liquid propellant rocket engines as they play a crucial role in maintaining a constant pressure of gas in the propellant lines. This, in turn, allows for the smooth operation of engine control valves, main propellant valves, gas generator valves, start systems, and most importantly, the pressurization of propellants for combustion. Pressure regulators in liquid propellant rocket engines can have different types. In this study, four different types of pressure regulators are mentioned. The differences, advantages and disadvantages of these regulator types are listed. The pressure regulator can be described as a small system consisting of many elements. In the study, the most important elements of the pressure regulator are listed one by one and the types of the elements are mentioned. The advantages and disadvantages of the types of these elements are listed. The design and manufacturing of the pressure regulators in space applications are always special to meet rigid requirements. The first step of designing an effective pressure regulator is mathematical model that considers the specific requirements and limitations of the application. In this thesis, the design, mathematical and dynamic modeling of the pressure regulator is carried out. The developed mathematical and dynamic model uses isentropic equations and force balance equations of the mechanical parts to create a more accurate representation of the regulator's behavior under real-world conditions. It also reveals variable models that may arise for variable conditions such as variable outlet volume. For example, pressure regulators with variable outlet volume use a different mathematical model, while pressure regulators with fixed outlet volume use a different set of equations. Using these developed mathematical and dynamic models, simulations are made for three different regulators with MATLAB Simulink. In this study, it is assumed that the pressure regulator has three control volumes. These control volumes are; inlet control volume, outlet control volume and sensing control volume. As the second step of the study, the requirements for designing the pressure regulator are defined. These requirements include important parameters such as inlet pressure, set pressure and mass flow rate. In addition to these parameters, the parameters of the working fluid also must be defined. Nitrogen and helium gases are used as working fluids in this study. In the third step of the study, the mechanical parameters of the pressure regulator should be determined. In order to determine the mechanical parameters, static calculations are made by using the mathematical model and the parameters are roughly calculated. Then the dynamic model on MATLAB Simulink is used with the optimization tool to obtain the optimum parameters. Optimum parameters are the inputs of the pressure regulators for the simulations. In this study, calculations of mechanical parameters were made only for the first regulator and other regulators were used to validate the dynamic model by comparing simulation and test results. Tests of three different pressure regulators are carried out in accordance with the requirements of each of them in the established pneumatic test setup. The data of these tests are collected from the pressure sensors on the line just before and after the pressure regulators and from the mass flow sensor in the line. In order to validate the accuracy of these developed mathematical and dynamic models, the simulations are made in MATLAB Simulink using the inputs in the test. And the results of the simulations obtained from this model is compared with the test results obtained from there different pressure regulators. After validation of the developed model, the simulations are made for three different regulators. The requirements and design inputs for each regulator are specified separately. These regulators differ in terms of dimensions, set pressure and mass flow rate variations, and the fluid they regulate. Simulations are performed with four different scenarios which include variations in inlet pressure, mass flow rate, and outlet volume for each regulator. All of the results of scenarios were compared among themselves for each regulator. In the results obtained, the effects of varying inlet pressure, mass flow rate and outlet volume on the outlet pressure of the regulator are observed. The model developed in this study provides valuable insight into how pressure regulators behave under different conditions and could help improve the design and performance of this critical component in future space applications.

##### Açıklama

Thesis (M.Sc.) -- Istanbul Technical University, Graduate School, 2023

##### Anahtar kelimeler

Aerospace industry,
Havacılık ve uzak endüstrisi,
Rocket engines,
Roket motorları