HVAC. HVAC is important in the design of medium to large industrial and office buildings such as skyscrapers and in marine environments such as aquariums, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors. Overview[edit] Heating, ventilating, and air conditioning is based on inventions and discoveries made by Nikolay Lvov, Michael Faraday, Willis Carrier, Reuben Trane, James Joule, William Rankine, Sadi Carnot, and many others.[1] The starting point in carrying out an estimate both for cooling and heating depends on the exterior climate and interior specified conditions.
However before taking up the heat load calculation, it is necessary to find fresh air requirements for each area in detail, as pressurization is an important consideration. In modern buildings the design, installation, and control systems of these functions are integrated into one or more HVAC systems. Heating[edit] Central heating unit. Ventilation (architecture) An air handling unit is used for the heating and cooling of air in a central location (click on image for legend). Ventilating (the V in HVAC) is the process of "changing" or replacing air in any space to provide high indoor air quality (i.e. to control temperature, replenish oxygen, or remove moisture, odors, smoke, heat, dust, airborne bacteria, and carbon dioxide). Ventilation is used to remove unpleasant smells and excessive moisture, introduce outside air, to keep interior building air circulating, and to prevent stagnation of the interior air. Ventilation includes both the exchange of air to the outside as well as circulation of air within the building.
It is one of the most important factors for maintaining acceptable indoor air quality in buildings. "Mechanical" or "forced" ventilation is used to control indoor air quality. Ventilation increases the energy needed for heating or cooling, however heat recovery ventilation can be used to mitigate the energy consumption. Windcatcher. An ab anbar with double domes and windcatchers in the central desert city of Naeen, near Yazd, Iran A windcatcher (Persian: بادگیر bâdgir: bâd "wind" + gir "catcher", Arabic: ملقف malqaf [1][2]) is a traditional Persian architectural element to create natural ventilation in buildings.[3] Windcatchers come in various designs: uni-directional, bi-directional, and multi-directional.
Windcatchers remain present in many countries and can be found in traditional Persian-influenced architecture throughout the Middle East, including in the small Arab states of the Persian Gulf (mostly Bahrain and Dubai), Pakistan and Afghanistan.[4] Background[edit] Central Iran shows large diurnal temperature variation with an arid climate. Most buildings are constructed from thick ceramics with high insulation values.
The windcatcher's effectiveness had led to its routine use as a refrigerating device in Persian architecture. A small windcatcher is called a shish-khan in traditional Persian architecture. Coandă effect. A spinning ping pong ball is held in a diagonal stream of air by the Coandă Effect. The ball "sticks" to the lower side of the air stream, which (in combination with the Magnus effect) stops the ball from falling down. The jet as a whole keeps the ball some distance from the jet exhaust, and gravity prevents it from being blown away. Discovery[edit] The lateral pressure which urges the flame of a candle towards the stream of air from a blowpipe is probably exactly similar to that pressure which eases the inflection of a current of air near an obstacle.
Mark the dimple which a slender stream of air makes on the surface of water. Bring a convex body into contact with the side of the stream and the place of the dimple will immediately show the current is deflected towards the body; and if the body be at liberty to move in every direction it will be urged towards the current...[3] Causes[edit] Applications[edit] The first Avrocar being readied at the Avro factory in 1958 Demonstration[edit] Fluid dynamics. Fluid dynamics offers a systematic structure—which underlies these practical disciplines—that embraces empirical and semi-empirical laws derived from flow measurement and used to solve practical problems.
The solution to a fluid dynamics problem typically involves calculating various properties of the fluid, such as velocity, pressure, density, and temperature, as functions of space and time. Before the twentieth century, hydrodynamics was synonymous with fluid dynamics. This is still reflected in names of some fluid dynamics topics, like magnetohydrodynamics and hydrodynamic stability, both of which can also be applied to gases.[1] Equations of fluid dynamics[edit] The foundational axioms of fluid dynamics are the conservation laws, specifically, conservation of mass, conservation of linear momentum (also known as Newton's Second Law of Motion), and conservation of energy (also known as First Law of Thermodynamics).
Conservation laws[edit] Above, is the viscous dissipation function. Solid mechanics. Solid mechanics is fundamental for civil and mechanical engineering, for geology, and for many branches of physics such as materials science. It has specific applications in many other areas, such as understanding the anatomy of living beings, and the design of dental prostheses and surgical implants. One of the most common practical applications of solid mechanics is the Euler-Bernoulli beam equation. Solid mechanics extensively uses tensors to describe stresses, strains, and the relationship between them. Relationship to continuum mechanics[edit] As shown in the following table, solid mechanics inhabits a central place within continuum mechanics.
Response models[edit] It is most common for analysts in solid mechanics to use linear material models, due to ease of computation. There are four basic models that describe how a solid responds to an applied stress: See also[edit] References[edit] Chandramouli, P.N (2014). J. Fluid mechanics. Brief history[edit] The study of fluid mechanics goes back at least to the days of ancient Greece, when Archimedes investigated fluid statics and buoyancy and formulated his famous law known now as the Archimedes' principle, which was published in his work On Floating Bodies - generally considered to be the first major work on fluid mechanics. Rapid advancement in fluid mechanics began with Leonardo da Vinci (observations and experiments), Evangelista Torricelli (invented the barometer), Isaac Newton (investigated viscosity) and Blaise Pascal (researched hydrostatics, formulated Pascal's law), and was continued by Daniel Bernoulli with the introduction of mathematical fluid dynamics in Hydrodynamica (1738).
Relationship to continuum mechanics[edit] Fluid mechanics is a subdiscipline of continuum mechanics, as illustrated in the following table. Assumptions[edit] Like any mathematical model of the real world, fluid mechanics makes some basic assumptions about the materials being studied. HVAC.