Browse Topic: Fire suppression
The design, testing, and analysis of a Guided Autorotative Delivery System (GADS) for suppression of incipient wildfires is described. The GADS consists of an unpowered 1 m diameter rotor, a control unit, and a payload of 2.2 kg of fire suppressant powder. On release from a fixed-wing UAV, the rotor passively deploys and enters autorotation, decelerating the payload and allowing precise delivery of the suppressant using cyclic pitch control. A numerical model of the system was developed to calculate the trajectory of the GADS during rotor deployment and descent, in the presence of ambient wind and cyclic pitch inputs. A reduced-scale model of the rotor was tested in a wind tunnel, and an uncontrolled full-scale, 1.5 kg prototype of the GADS was fabricated and tested by dropping from a hovering quadcopter as well as a fixed-wing UAV. The full-scale drop experiments validated the deployment and autorotation stability of the system, and demonstrated that the GADS maintains descent velocities suitable for incipient fire suppression (≈ 5 m/s). Numerical predictions indicate that the GADS descent trajectory can be controlled with cyclic pitch in an ambient crosswind of at least 5 m/s (10 kts). Measurements captured during the drop tests using onboard instrumentation show good qualitative agreement with numerical predictions. Future work will include drop tests with remotely controlled cyclic pitch, followed by fully autonomous controlled descent. The study establishes design guidelines for guided autorotative systems and illustrates their potential for scalable UAV-based wildfire suppression or emergency response.
The emergence of electric Vertical Takeoff and Landing (eVTOL) air vehicles is transforming how people and freight are moved in short distances. This transformation has a profound impact on surrounding infrastructure necessary to provide Aircraft On Ground support for eVTOLs. The hover capabilities of eVTOLs have similar operating characteristics within terminal and uncontrolled airspace. However, the need to conserve battery energy via rapid approaches and departures affects terminal airspace management. To attract eVTOL operators, existing airports, landing zones, and vertiports are modifying their infrastructure to include fixed electric charging stations, additional taxiways, upgraded fire suppression systems, separate hangers, and capable MRO facilities. Augusta Regional Airport (KAGS) is the base airport for the annual Masters Golf Tournament which experiences five times the normal airport traffic and some 40,000 commuting patrons. eVTOLs can offset land traffic issues associated with commuters and supplies. Since KAGS is centroid to 32,000 square miles of territory void of major highways, basing eVTOLs can offer expedited transit services for people and goods which will have a profound impact on the economic viability and quality of life in the area.
Smoldering peat fires are the largest fires on Earth. They ignite very easily, are notoriously difficult to put out, and release up to 100 times more carbon into the atmosphere than flaming fires, contributing to climate change. These fires are known as “zombie fires” for their ability to hide and smolder underground and then reanimate as new flames days or weeks after the wildfire had been extinguished.
A hyperbaric chamber has been designed to achieve the goals of maximizing safety, minimizing complexity, and minimizing cost of hyperbaric chamber therapy. This design minimizes the volume of compressed gas in the chamber, and eliminates the need for complex gas mixing, carbon dioxide scrubbing, thermal management, and fire suppression systems. The simple pressurization system affords safe operation by minimally trained personnel. It requires only clean water and small volumes of compressed oxygen, and uses no electrical power. These features allow the chamber to be used in remote, undeveloped locations where hyperbaric oxygen therapy is currently not feasible.
A hyperbaric chamber has been designed to achieve the goals of maximizing safety, minimizing complexity, and minimizing cost of hyperbaric chamber therapy. This design minimizes the volume of compressed gas in the chamber, and eliminates the need for complex gas mixing, carbon dioxide scrubbing, thermal management, and fire suppression systems. The simple pressurization system affords safe operation by minimally trained personnel. It requires only clean water and small volumes of compressed oxygen, and uses no electrical power. These features allow the chamber to be used in remote, undeveloped locations where hyperbaric oxygen therapy is currently not feasible.
The use of Heavy Vehicle Event Data Recorders (HVEDRs) in collision analysis has been well recognized in past research. Numerous publications have been presented illustrating data accuracy both in normal operating conditions as well as under emergency braking conditions. These data recording devices are generally incorporated into Electronic Control Modules (ECMs) for engines or Electronic Control Units (ECUs) for other vehicular components such as the Anti-Lock Brake System. Other research has looked at after-market recorders, including publically-available Global Positioning System (GPS) devices and fleet management tools such as Qualcomm. In 2009, the National Fire Protection Association (NFPA) incorporated a Vehicle Data Recorder (VDR) component into their Standard for Automotive Fire Apparatus. The purpose of this was to “…capture data that can be used to promote safe driving and riding practices.” The Standard requires minimum data elements, recording times, and sample rates. These include vehicle speed, acceleration, throttle position, and other specified parameters. While the NFPA is not a regulatory agency, it serves to bring representatives from the fire suppression industry together to set accepted practices and standards. It was the intent of this research to validate the data imaged from a Weldon Type 6444 VDR as employed by fire vehicles. Data were compared to an external VBOX 3i measuring device, as well as internal J1939 Controller Area Network (CAN) data from the vehicle. Testing also incorporated an element designed to ensure that data were retained following a catastrophic loss of power. The results of this study demonstrate that the NFPA compliant Weldon Type 6444 as tested can be used with confidence during a collision investigation.
America's pony cars are a favorite of racers and fans alike, so racing them against each other is natural. Detroit's pony car category has been consistently popular with both car buyers and racing fans, so it makes sense that the U.S. automakers would pursue venues for racing their sporty 2+2s against each other. Longtime fans regard the late-1960s/early-1970s period the glory days for the Trans Am racing series because that was when Ford's Mustang, Chevrolet's Camaro, American Motors' AMX, and Dodge's Challenger engaged in legendary battles on tracks across North America.
This SAE Aerospace Information Report (AIR) provides background information, technical data and related technical references for minimization of electrostatic hazards in aircraft fuel systems. Techniques used to minimize the electrostatic hazard include: a Reducing fueling rate into tank bays including use of multiple refueling inlet nozzles. b Reducing refuel plumbing flow velocities. c Introducing fuel into the tank at a low velocity near the bottom and directing it to impinge upon a grounded conducting surface. d Avoiding electrically isolated conductors in the fuel tank. e Using conductivity additives in the fuel.
This paper presents a recently developed method meant to act as a tool for objectively assessing and comparing the performance of automatic fire suppression systems. This methodology specifies requirements and procedures for evaluating the efficiency and performance of automatic fire suppression systems permanently installed in the engine compartments of buses and coaches. The testing is done according to SP method 4912 and carried out in a test enclosure where the fire performance of different suppression systems can be objectively assessed in a well-defined way. The test methodology includes a battery of fire tests simulating different engine loads, air flows and fire scenarios. Every tested system is rated according to its performance. The test method also includes testing of re-ignition due to hot surface ignition of liquid fuels.
This paper presents a fire suppression analysis for the Altair project. The architecture of the Altair systems relevant to fire safety is briefly reviewed. This is followed by an outline of a fire safety analysis of the spacecraft including an outline of a probabilistic risk analysis (PRA). The particular emphasis of this analysis is the change in risk as the vehicle moves to lower pressure, higher operating voltage and increased oxygen mole fraction. The analysis shows that all of these changes increase the likelihood and intensity of a fire. The paper then outlines the options for a suppression system followed by a trade analysis of the different options. The candidate systems include inert gas agents (nitrogen, carbon dioxide and helium), water-based systems (spray, mist and foam) and chemically active agents. Chemically active agents are included for reference purposes since they are not likely candidates for the Altair vehicles.
Items per page:
50
1 – 50 of 63