In fluid dynamics, laminar flow is characterized by fluid particles following smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. At low velocities, the fluid tends to flow without lateral mixing, and adjacent layers slide past one another like playing cards. There are no cross-currents perpendicular to the direction of flow, nor eddies or swirls of fluids. In laminar flow, the motion of the particles of the fluid is very orderly with particles close to a solid surface moving in straight lines parallel to that surface. Laminar flow is a flow regime characterized by high momentum diffusion and low momentum convection.
Displacement may refer to:
A hydraulic fluid or hydraulic liquid is the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water. Examples of equipment that might use hydraulic fluids are excavators and backhoes, hydraulic brakes, power steering systems, automatic transmissions, garbage trucks, aircraft flight control systems, lifts, and industrial machinery.
Buoyancy, or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the displaced fluid.
A fire hydrant or firecock (archaic) is a connection point by which firefighters can tap into a water supply. It is a component of active fire protection. Underground fire hydrants have been used in Europe and Asia since at least the 18th century. Above-ground pillar-type hydrants are a 19th-century invention.
Diuresis is increased urination (polyuria) or, in the related word senses more often intended, the physiologic process that produces such an increase or the administration of medications to encourage that process. It involves extra urine production in the kidneys as part of the body's homeostatic maintenance of fluid balance.
Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces. Archimedes' principle is a law of physics fundamental to fluid mechanics. It was formulated by Archimedes of Syracuse.
A tap is a valve controlling the release of a liquid or gas.
A gate valve, also known as a sluice valve, is a valve that opens by lifting a barrier (gate) out of the path of the fluid. Gate valves require very little space along the pipe axis and hardly restrict the flow of fluid when the gate is fully opened. The gate faces can be parallel but are most commonly wedge-shaped.
A backflow prevention device is used to protect potable water supplies from contamination or pollution due to backflow.
Birdsill Holly Jr. was an American mechanical engineer and inventor of water hydraulics devices. He is known for inventing mechanical devices that improved city water systems and patented an improved fire hydrant that is similar to those used currently for firefighting. Holly was a co-inventor of the Silsby steam fire engine. He founded the Holly Manufacturing Company that developed into the larger Holly Steam Combination Company that distributed heat from a central station and developed commercial district heating for cities in the United States and Canada.
In North America, a standpipe is a type of rigid water piping which is built into multi-story buildings in a vertical position, or into bridges in a horizontal position, to which fire hoses can be connected, allowing manual application of water to the fire. Within the context of a building or bridge, a standpipe serves the same purpose as a fire hydrant.
A water tender is a type of firefighting apparatus that specialises in the transport of water from a water source to a fire scene. Water tenders are capable of drafting water from a stream, lake or hydrant.
This is a glossary of firefighting equipment.
A wildland water tender is a specialized vehicle capable of bringing water, foam, or dry chemicals to fire trucks in the field that are engaged on the fireline. Water tenders have a large truck mounted tank that carries a minimum 1,000 gallons and up to 4,000 gallons of water. These vehicles are specifically designed for fire fighting often with four-wheel drive, rugged suspension and high wheel clearance for mountainous dirt road conditions. According to the National Fire Protection Association, if the apparatus will be used primarily for outdoor and wildland responses, then it is to be considered a wildland fire apparatus and must conform to NFPA 1906.
Hondo Dog Park is a city park in Hillsboro, Oregon, United States. Opened in 2007, it is the first dog park in that city. Located on nearly four acres, the park is in the northeast section of Hillsboro adjacent to Hillsboro Stadium. Hondo Dog Park is named after a Hillsboro Police Department K-9 unit dog that was shot and killed in the line of duty. The park includes a fire hydrant painted like an American flag as a memorial to the police dog, which received some controversy when the park opened.
The Auxiliary Water Supply System is a high pressure water supply network built for the city of San Francisco in response to the failure of the existing emergency water system during the 1906 earthquake. It was originally proposed by San Francisco Fire Department chief engineer Dennis T. Sullivan in 1903, with construction beginning in 1909 and finishing in 1913. The system is made up of a collection of water reservoirs, pump stations, cisterns, suction connections and fireboats. While the system can use both fresh or salt water, it is preferential to not use salt water, as it commonly causes galvanic corrosion in fire equipment.
The Community Fire Safety Act of 2013 is a bill that would prevent the Environmental Protection Agency from requiring that all new fire hydrants in the United States be lead-free beginning in 2014. The bill was passed by the United States House of Representatives during the 113th United States Congress.
A water distribution system is a part of water supply network with components that carry potable water from a centralized treatment plant or wells to consumers to satisfy residential, commercial, industrial and fire fighting requirements.
