Browse Topic: Rocket engines
Rocket projectiles are a type of ammunition that get their power from rocket engines. Long-range guided rockets, in particular, hold great significance as they seem to mark the way forward in modern warfare. These guided projectiles take full advantage of the considerable range that long-range rockets offer and, at the same time, manage to achieve improved accuracy. This paper delves into a model that is used for predicting the impact point of rocket projectiles, with the application of the proportional navigation guidance law. It also undertakes an analysis of both the strengths and the weaknesses of this model. Through the formulation of equations related to the dynamics of the center of mass and some other supplementary equations, a rather comprehensive trajectory equation was worked out. When this trajectory was simulated, it brought about the creation of a firing table, which is of help in predicting the initial trajectory inclination angle.
Gaganyaan is an ambitious and recover safety mission for the Indian space program to launch humans into space. The success of the mission depends on the development of required technology and systems. A test vehicle is developed for the technological demonstration for all envisioned abort flight scenarios of Gaganyaan mission. A new configuration of launch vehicle with single liquid stage is planned for multiple flights. Coupled Loads analysis of launch vehicle system is a standard practice to estimate response and loads for the design of structures and generating sine vibration test levels. Usually a vehicle rests on the launch pad through base shroud with horizontal support and no vertical restraint. Upon ignition of the engine, thrust builds up and upon overcoming gravity the vehicle takes off. In the current analysis the launch vehicle is held in position using a holding / retracting mechanism and at a predefined time the vehicle is released. The boundary condition required a novel method to perform response analysis. The responses estimated from pre-flight analysis is correlated with flight response and a good correlation is observed. Additionally response analysis is performed at engine shut-off. Being the first flight, no flight data was available of engine thrust. In the current work, using an analytical thrust, responses are estimated. The analysis also helped in generating levels for vibration test of various sub-assemblies and payload.
For decades, researchers have recognized the potential of rotating detonation engines (RDEs) in powering the next generation of hypersonic air-breathing engines, rocket engines, and stationary power generation gas turbine systems. But realizing the potential has been fraught with challenges.
NASA is developing a lightweight one-piece regeneratively cooled thrust chamber assembly (TCA) for liquid rocket engines. Liquid rocket engines create thrust through the expansion of combusted propellants within the TCA. Standard manufacturing of TCAs involves individually building the injector, main combustion chamber and nozzle, and then bolting or welding the components together at the joints. However, potential seal failures in these complex joints can cause catastrophic explosions, as in the tragedy of the Space Shuttle Challenger.
Hypersonic propulsion would allow for air travel at speeds of Mach 6 to 17, or more than 4,600 to 13,000 miles per hour, and has applications in commercial and space travel.
In the fall of 2023, NASA hot fire tested an aluminum-based, 3D-printed rocket engine nozzle. What made the event remarkable is that aluminum isn’t typically used for additive manufacturing because the process causes it to crack, and it isn’t used in rocket engines due to its low melting point. Yet the test was a success.
Engineers at NASAs Stennis Space Center have developed the HYdrocarbon Propellants Enabling Reproduction of Flows in Rocket Engines (HYPERFIRE), a sub-scale, non-reacting flow test system. HYPERFIRE uses heated ethane to enable physical simulation of rocket engines powered by a broad range of propellants in an inexpensive, accurate, and simple fashion.
Airplane turbines and rocket engines are very powerful, hot and noisy and yet in need of extremely sensitive measurement technology. And they have another thing in common: They are most efficient when they run on a constant and even flame. Specialized measurement technology helps aerospace engineers improve combustion chambers and fuel injectors. In Switzerland, two ambitious student organizations have been using iterative pressure measurements to develop and build a significantly more efficient next generation of rocket engines.
In any human space flight program, safety of the crew is of utmost priority. In case of exigency in atmospheric flight, the crew is safely and quickly rescued from the launch vehicle using Crew Escape System (CES). CES is a critical part of the Human Space Flight which carries the crew module away from the ascending launch vehicle by firing its rocket motors (Pitch Motor (PM), Low altitude Escape Motor (LEM) and High altitude Escape Motor (HEM)). The structural loads experienced by the CES during the mission abort are severe as the propulsive, aerodynamic and inertial forces on the vehicle are significantly high. Since the mission abort can occur at anytime during the ascent phase of the launch vehicle, trajectory profiles are generated for abort at every one second interval of ascent flight period considering several combinations of dispersions on various propulsive parameters of abort motors and aero parameters. Depending on the time of abort, the ignition delay of PM, LEM and HEM are adjusted in order to minimize the lateral acceleration on the vehicle, at the same time meeting the horizontal range requirement. Aerodynamic load distributions on the vehicle and aero forces and moments on the Grid fin are generated for various Mach No., Angle of Attack (AoA) combinations for jet ON and jet OFF conditions of PM, LEM and HEM. In order to estimate the structural loads for CES during abort, inertia relief analyses are carried out for static load on a free-free finite element model at all the time instances in the abort trajectory as a time sweep simulation considering the appropriate aerodynamic forces, propulsive parameters (mass consumption and thrust) and trajectory parameters (Mach No., Dynamic Pressure and AoA) at each time instant in the trajectory. During abort at lower altitude along with LEM, Pitch Motor (PM) is fired perpendicular to the axis of the vehicle to turn the vehicle towards the sea thereby increasing the AoA and bending moment on the vehicle. The Pitch Motor thrust acting perpendicular to the vehicle excites the first bending mode and augments the Bending Moment. LEM thrust and HEM thrust acting along the vehicle axis also can excite the axial modes of the vehicle. Similarly the lateral aero dynamic forces on the vehicle excite the lateral dynamics of the vehicle whenever there is a sudden change in the AoA due to wind gust. To account for the flexible body dynamic forces, a load augmentation factor called Flexibility Factor is multiplied on the static loads to arrive at the limiting loads on the vehicle. This paper briefly explains the structural load estimation methodology for CES abort, various inputs required and different steps involved in it.
L3Harris Technologies Melbourne, FL 585-465-3592
Skoltech engineers have used a 3D printer to fabricate — and investigate the mechanical characteristics of — samples of bronze-steel alloys previously unknown to materials science. Blending the distinct properties of bronze and steel, the novel alloys could be used to manufacture combustion chambers for aircraft and rocket engines. These would benefit from both steel’s ability to withstand extreme temperatures and bronze’s capacity to conduct heat away from the chamber.
Inflatable and deployable beams and masts such as solar sail supports used in space missions are often made of polymer composites and may be stored for one to two years in space before deployment. While stored, these polymer composites degrade on a molecular level, which can limit the ability of the beams to unfurl properly, reducing performance or even failing to unfurl. Researchers at NASA’s Langley Research Center developed a fiber-reinforced polymer composite to reduce the effect of viscoelastic creep and prolong the molecular integrity of polymer-based beams over time.
It’s no longer a question of when metal additive manufacturing (AM)—and particularly metal laser powder-bed fusion (LPBF)—will become an accepted, reliable production technology, particularly in aerospace and defense. This is already the case now. Over the past 18 months a host of aerospace leaders, OEMs, startups, and contract manufacturers (CMs) alike have purchased, or begun outsourcing work to, advanced AM systems. They’re confidently producing end-use, 3D-printed parts—and sometimes entire rocket engines.
Letter from the Guest Editors
The primary objective of any test program is to maximize the probability, within programmatic constraints, that the flight design will function properly and successfully when used in actual service for the intended application. Flight risks are mitigated via prudent and effective analysis and testing. While analysis can sometimes be used in place of test, proper analytical techniques utilize test data as the basis for model correlations. The combination of analysis and test verification is used for both qualification of the LRE design as well as workmanship verification of each LRE flight unit.
Hyperganic Munich, Germany
Loose particles inside the additional pipe of a rocket engine are an important factor that causes propulsion system failure. For loose particles inside the additional pipe, it is necessary not only to determine whether they exist or not, but also to locate them for subsequent processing. Due to the complex structure of the additional pipe, the uneven medium used for sound wave transmission, and the anisotropic speed of the sound. Thus, it is difficult to determine the locations of loose particles by using the traditional time difference localization method. Aiming at this problem, this article proposed a localization method of loose particles based on Chaos Theory and Particle Swarm Optimization-Back-Propagation Neural Network (PSO BP Neural Network). First, chaotic characteristics of collision signals generated by loose particles are studied. On this basis, the localization method of loose particles based on PSO BP Neural Network is proposed, which uses the correlation dimension, Lyapunov exponent, and the Kolmogorov entropy (K entropy) as localization features. The test results show that the proposed loose particle localization method can effectively locate loose particles inside a section of broken line pipe, which is composed of composite materials and have a certain internal structure. The method can theoretically be applied to the localization of collision signals with similar generation mechanism.
Researchers have used the ancient Japanese art of paper folding to possibly solve a key challenge for outer space travel: how to store and move fuel to rocket engines. They developed an origami-inspired, folded plastic fuel bladder that doesn’t crack at super-cold temperatures and could someday be used to store and pump fuel.
Researchers have developed a rocket propulsion system, known as a rotating detonation rocket engine, that will allow upper stage rockets for space missions to become lighter, travel farther, and burn more cleanly.
NASA Glenn researchers developed a new oxide dispersion strengthened medium entropy alloy (ODS-MEA) via additive manufacturing (AM). ODS alloys, in which nanoscale ceramic particles are distributed within the metal, were originally developed to enhance mechanical properties (e.g., creep resistance, tensile strength, microstructure integrity) at extreme temperatures. Such alloys show promise for metal components of gas turbines, rocket engines, nuclear reactors, and other high-temperature applications; however, the conventional mechanical alloying process to produce such alloys is highly inefficient, time-consuming, and costly.
The advent of multi-rotor, electric VTOL aircraft capable of carrying passengers and providing on-demand personal air transport promises a revolution not only in urban travel, but also in a multitude of other applications which will change the way that a broad range of people carry out their routine work activities. Many of the eVTOL design projects propose to use current ballistic parachute systems in case of any power or control failure; however, any recovery system which (i) gives a Ground Contact Velocity (GCV) of 5 to 8m/s and (ii) will not deploy properly below c. 100 to 150 feet will not be a solution that should satisfy certification requirements for carrying fare-paying passengers above a crowded urban environment. This paper updates the detailed design and function of the rocket motors and control system designed to provide a controlled landing at less than 2m/s in any emergency situation.
Founded on July 1, 1960, Marshall Space Flight Center in Huntsville, AL is one of NASA’s largest field centers. Marshall engineers designed, built, tested, and helped launch the Saturn V rocket that carried Apollo astronauts to the Moon. Marshall developed new rocket engines and tanks for the fleet of space shuttles, built sections of the International Space Station (ISS), and now manages all the science work of the astronauts aboard the ISS from a 24/7 Payload Operations Integration Center. Marshall also manages NASA’s Michoud Assembly Facility in New Orleans — the agency’s premier site for the manufacture and assembly of large-scale space structures and systems.
Rocket engine testing requires a lot of light since all tests are filmed with high-speed cameras to monitor performance; however, those cameras have to adjust to the bright plume from a firing engine, which would black out the rest of the image. Traditionally, that light has been provided by metal halide bulbs.
NASA Johnson Space Center developed reprogrammable and interchangeable electronic controllers that can attach to a system or subsystem wirelessly or through plug-and-play capability. Originally designed to work with rocket engines, this technology can control different systems and subsystems. This smart controller recognizes which system it is communicating with once connected to the network and loads the appropriate application to perform the required function in the system. The device enables a common set of spares and can talk to other devices of its kind by relaying information and instructions to other controllers. A prototype can be easily developed using low-cost solutions such as Raspberry Pi to demonstrate functionality.
Items per page:
50
1 – 50 of 347