Browse Topic: Gravity
We are in the midst of a golden age of space travel with the upcoming launch of multiple reusable heavy lift rockets. These new craft will increase deliverable mass to LEO and decrease delivery costs. These rockets are essential to replacing the ISS with commercial space stations in the coming decade. These new commercial stations will enable the creation of in-space factories that leverage microgravity to improve products for use on Earth. Large-scale 3D bioprinting is one technology that will benefit from microgravity and has the potential to address the organ shortage and overreliance on animal models for drug discovery and testing
Recent experiments by a team from the West Virginia University focused on how a weightless microgravity environment affects 3D printing using titania foam, a material with potential applications ranging from UV blocking to water purification. ACS Applied Materials and Interfaces published their findings
For both space tourism and space exploration, there is an interest in generating artificial gravity in space for entertainment, recreational, and scientific purposes, as well as to counter the health concerns of extended exposure to a microgravity environment. NASA Ames Research Center has developed a novel technology — a system and approach for creating artificial gravity using a non-rotating spacecraft with connected moving modules, which can be used for habitation and other purposes
NASA asks hard questions: What’s it like on the Moon? Has there been life on Mars? How did the first stars form? Finding these big answers often means first solving a series of smaller but equally vexing questions. For example, how does prolonged weightlessness change the way the brain controls muscles? How does the brain control muscles? Before sending humans on the long journey to Mars, NASA wants to better understand the effects the trip will have on astronauts. Now a company that helped the space agency try to solve these questions is helping others find answers as exciting as any NASA discovery
Nowadays, the technology war always shows the need for rushing hours in the transportation sector. Turbines and IC engines, which generate power, can only be operated with the help of high-pressure air. In this research, an analytical study introduces an innovative boat vehicle driven by air-water interactions. The principles of an OWC (Oscillating Water Column) wave energy converter device is reviewed to find the effects of air-water interactions that are the key concepts for introducing the partially levitated transportation method. The physical conditions around the boat vehicle, such as squat conditions and speed variations, are reviewed under different stream conditions to explore the possibilities of converting the potential energy of water into kinetic energy under dynamic conditions. An experimental Froude - model analysis is presented to find the velocity and kinetic energy at upstream and downstream conditions of the channel. A 1D analytical method using Matlab is performed
A person who is inactive for an extended period of time (such as when they have a long illness) loses strength as well as muscle and bone mass. Astronauts on the International Space Station (ISS) face similar risks because bones and muscles begin to atrophy in the absence of gravity. Resistive exercise, where the musculoskeletal system bears weight, has been shown to mitigate these effects. But just lifting weights, as we do on Earth, does not work without gravity
As NASA develops plans for increasingly ambitious human missions, including a return to the Moon and, eventually, exploration of Mars, more advanced medical risk assessment is necessary in order to keep astronauts healthy. Many aspects of spaceflight can contribute to risk, including altered gravity (which effects blood distribution and vascular biology, muscles, and bones), confinement, changes in sleep patterns, and challenges related to pharmaceutical administration and nutrition. Perhaps the one aspect of the space environment that poses the greatest risk is space radiation. Space radiation consists of energetic protons and helium ions from the sun, as well as galactic cosmic rays — high energy protons and energetic heavy ions — from outside our solar system
Numerical prediction of a confined, co-flowing, laminar jet diffusion flame has been investigated under sinusoidal “g-jitter” to describe the flame structure; this type of flame-body force interaction is typical of a microgravity environment such as in the spacecraft. We introduced g-jitter in the direction orthogonal to the fuel and air inflow. We show that the lower frequencies (0.1-0.5 Hz) of sinusoidal g-jitter significantly affected the flame geometry and behavior. The majority of the flame structure was found to oscillate directly in response to the imposed g-jitter. It has also been observed that nonlinearity in the response behaviors is more prominent in the reaction zone of the flame
Through dynamic computational simulations it is possible to achieve a high reliability index in the development of automotive components, thus reducing the time and cost of the component can generate considerable levels of competitiveness and quality. This work suggests the validation of a methodology to create the virtual routes to find the best design of the flexible components influenced by force of gravity, thermal expansion or even the static balance between the anchor points and used to be designed and installed in the vehicle always in the nominal condition which in many cases diverge from the physical. With the difficulty of predicting mathematically the nonlinear relations of deformation and motion under the effect of forces and moments, we use the NX9 software in the creation of the dynamic movement motion to the motor and transmission assembly imposes on the flexible components through a routine mapped by Cartesian coordinates, simulating the characteristic movements of the
This SAE Recommended Practice establishes minimum performance requirements and test procedures for evaluating and testing passenger car side door latch systems. It is limited to tests that can be conducted on uniform test fixtures and equipment in commercially available laboratory test facilities. The test procedures and minimum performance requirements outlined in this document are based on currently available engineering data. It is intended that all portions of the document will be periodically reviewed and revised, as additional knowledge regarding vehicle latch performance under impact conditions is developed
This SAE Standard defines the requirements for an oil to be used in the SAE HS 806 Oil Filter Test Procedures
This research deals with the problem of modelling the orbit and attitude motion of uncontrolled manmade objects in orbit about the Earth, which tumble due to the natural influences of the near-Earth space environment. A mathematical, physics-based and computational approach is taken to model the forces and torques that drive the orbit and attitude evolution of such objects. The main influence modelled is solar radiation pressure (SRP), which is the interaction of solar electromagnetic radiation with the surface of an object, leading to both forces and torques that influence the orbital and attitude motion. Other influences, such as the gravitational field of the Earth, are also modelled
This aerospace recommended practice is applicable to the design of a reusable locking device for cylindrical nuts which are generally tightened with a spanner wrench. Nuts of this type are commonly used to pre-load, and/or position, anti-friction bearings
This recommended practice covers methods for measuring or evaluating five properties or characteristics of sintered carbide which contribute significantly to the performance of sintered carbide tools. These properties are: hardness, specific gravity, apparent porosity, structure, and grain size. They are covered under separate headings below
Experiments of flame-spread of fuel droplets have been performed in microgravity actively. However, the experiment has limitation in the number of droplets due to relatively short microgravity durations in the ground based facilities. It is difficult to conduct flame spread experiments of large scale droplet clouds in microgravity. This study conducted simulation of flame-spread behavior in randomly distributed large-scale droplet clouds by using a percolation approach, in order to make a theoretical link the gap between droplet combustion experiments and spray combustion phenomenon with considering two-droplet interaction. Droplets are arranged at lattice points in 2D lattice. The occurrence probability of group combustion (OPGC) is calculated as a function of the mean droplet spacing (S/d0)m. The (S/d0)m for 0.5 OPGC is defined as the critical mean droplet spacing (S/d0)critical, which separates the droplet cloud into two groups if the lattice size becomes infinity; relatively dense
It may be possible to generate high power / high frequency gravitational waves (HFGWs) by high frequency accelerated axial rotation (spin) and/or accelerated high frequency vibration of an electrically charged, possibly asymmetric structure, within the context of non-equilibrium thermodynamics, namely far-from-equilibrium physics, highly non-linear in nature. The structure which is the HFGW generator (HFGWG), has the ability to control the accelerated modes of vibration and spin of its electrically charged surfaces, in particular the rapid rates of change of accelerated-decelerated-accelerated vibration and/or accelerated-decelerated-accelerated gyration (axial spin) of these electrified surfaces, in this manner delaying the onset of relaxation to thermodynamic equilibrium, thus generating a physical mechanism which may induce anomalous effects. Under certain conditions, involving rapid acceleration transients, it is observed that there will be exponential growth in electromagnetic
Researchers at NASA's Armstrong Flight Research Center have developed a new technology to reduce inaccuracies in force/haptic feedback devices and systems. Used at NASA in aircraft simulations for force feedback pilot controls, these systems involve a servo motor applying precise force to a specific point based on very accurate measurements. However, because the force instrumentation often cannot be placed directly at the point of interest, a mechanical assembly is used, linking the force transducer to the target point. Unfortunately, this mechanical assembly introduces inaccuracies due to its own forces of gravity, friction, and inertia
Researchers at NASA’s Marshall Space Flight Center (MSFC) have developed a novel point mechanic piezoelectric system capable of sensing extremely small vibrations, forces, or strains. The system’s high sensitivity near resonance and low noise floor enable the sensor to detect various low-frequency parameters — such as miniscule changes in the gravity gradient, seismic waves, and acoustics — from minimum detectable signals in the surrounding environment. Traditional piezoelectric systems, such as gravity gradiometers and seismometers, have larger intrinsic noise and smaller signal-to-noise ratio, thus requiring more complex instrumentation (and often larger, more expensive, and more cumbersome instrumentation). NASA’s innovative point mechanic sensor instead uses a simple and unique system to detect minute parameter changes, leading to significantly lower cost and material requirements
The motivation for this paper is to predict the flow of water over exterior surfaces of road vehicles. We present simulations of liquid flows on solid surfaces under the influence of gravity with and without the addition of aerodynamic forces on the liquid. This is done using an implementation of a Coupled Level Set Volume of Fluid method (CLSVOF) multiphase approach implemented in the open source OpenFOAM CFD code. This is a high fidelity interface-resolving method that solves for the velocity field in both phases without restrictions on the flow regime. In the current paper the suitability of the approach to Exterior Water Management (EWM) is demonstrated using the representative test cases of a continuous liquid rivulet flowing along an inclined surface with a channel located downstream perpendicular to the oncoming flow. Experimental work has been carried out to record the motion of the rivulet in this case and also to measure the contact angle of the liquid with the solid surface
Electron Beam Freeform Fabrication, or EBF3, is a process that uses an electron beam gun, a dual wire feed, and computer controls to manufacture metallic structures for building parts or tools in hours, rather than days or weeks. EBF3 can manufacture complex geometries in a single operation, and provides efficient use of power and feedstock. The technology has a wide range of applications, including automotive, aerospace, and rapid prototyping. It can build large metallic parts measuring feet in length, and has been reduced in size and power to enable zero-gravity experiments conducted on NASA's Reduced Gravity aircraft
Measurements of the cosmic microwave background are a powerful probe of the early universe. Part-per-million fluctuations in the intensity of background trace the initial conditions of matter and energy shortly after the Big Bang, mapping the large-scale structure of spacetime. Now, new measurements in linear polarization at sensitivities of a few parts per billion can look behind these initial conditions to test physics at energies a trillion times higher than terrestrial accelerators, and perhaps even provide a glimpse of quantum gravity in action
Specific gravity is a nondestructive test used as a quality control check of the consistency of formulation and processing of brake lining. The specific gravity and the range of specific gravity are peculiar to each formulation and, therefore, the acceptable values or range must be established for each formulation by the manufacturer. Specific gravity alone shows nothing about a materials in use performance. The specific gravity of sintered metal powder friction materials, particularly those which have steel backing members, is usually determined somewhat differently. Reference ASTM B 376
NASA's Langley Research Center has developed a method and apparatus to be used for cell culture that combines the effects of microgravity and low-dose radiation. The technology has been developed to simulate the effects of microgravity and chronic radiation exposure to cell culture experiments conducted on the International Space Station (ISS
This technology allows one to test small-body surface mobility and sampling systems in the laboratory. It is capable of simulating a microgravity environment with relevant terrain. The magnitude of the gravity, the terrain properties, and the surface system being tested are all easily modified to allow for a broad range of experimental setups
The following SAE Recommended Practice furnishes sample forms for helical compression, extension and torsion springs to provide a uniform method for specifying design information. It is not necessary to fill in all the data, but sufficient information must be supplied to fully describe the part and to satisfy the requirements of its application. For detailed information, see “Design and Application of Helical and Spiral Springs - SAE HS 795”, also “Helical Compression and Extension Spring Terminology - SAE J1121”. Both of these documents use SI (metric) Units in accordance with the provisions of SAE TSB 003, as does SAE J1122. Here, however, the U.S. Customary Units (in, lb, psi) have been added in parentheses after each SI Unit for the convenience of the user who must furnish specifications on a project where all requirements are listed in non-metric terms
To train astronauts to live and work in the weightless environment on the International Space Station, NASA employs a number of techniques and facilities that simulate microgravity. Engineers at the NASA Johnson Space Center (JSC) have developed a new system called the Active Response Gravity Offload System (ARGOS) that provides a simulated reduced gravity environment within a confined interior volume for astronauts to move about and/or equipment to be moved about as if they were in a different gravity field. Each astronaut/item is connected to an overhead crane system that senses their actions (walking or jumping, for example) and then lifts, moves, and descends them as if they had performed the action in a specified reduced gravity
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