Green approach of building design: natural ventilation
Designing a proper ventilation system is integral to building & facility planning, because it is has direct impact on safety and health of the occupants. Also, an environment friendly building with proper ventilation system reduces the energy cost significantly . The principal goal of a ventilation unit is to provide thermal comfort and good indoor Continue reading
CFD analysis for process industry : basket strainer
Strainers are used in processing plants and chemical industry as a filtering device. The filtration process involves flow through narrow passages, which causes high pressure drop or head-loss. Besides the losses in filter screens, there are other component of head loss such as during entry and exit pipes, also due to expansion and contraction at Continue reading
Finite volume method for computational fluid dynamics (CFD)
Finite volume method (FVM) is a technique, that is used to solve the governing partial differential equations (PDEs) for fluid flow and heat transfer. While the actual governing PDEs can’t be solved analytically for complex domain, FVM solves them by converting to algebraic equations. In this method the equations are solved at finite number of Continue reading
Smoke analysis & evacuation simulation : car parking analysis
Indoor Car parks are generally constructed in multistory apartments, shopping complex, hospitals, theaters and other commercial spaces. The general difficulties that are faced in the indoor car parks under normal conditions are increased level of carbon monoxide concentration and carbon dioxide concentration. In order to bring the concentration levels under control (ventilation) jet fans are Continue reading
CFD analysis for Turbomachinery : verification of performance curve of a fan
Axial flow fan has wide range of application in industry. The main usage of the axial flow fan is to provide the forced ventilation. The size and the performance of the fan will change depending upon the type of the application used. For example for circuit board cooling in the CPU small fans are used. Continue reading
CFD analysis of clean rooms for contamination tracking
Clean rooms or sterile facilities are maintained under a conditioned space. Several engineering fields such as the aerospace industry, the semiconductor industry, hospitals and pharmaceuticals need to maintain clean-rooms.. Clean rooms are spaces where the concentration of unwanted foreign particles and environmental conditions must be maintained in a stringent manner. For instance, the presence of Continue reading
Significance of Courant number for stability and convergence of CFD simulations
What is Courant number ? Courant-Friedrichs-Lewy (CFL) condition is absolutely essential in solving the partial differential equations. This non dimensionless number arises while solving the time marching problems. This condition is named after the respective scientists Richard Courant, Kurt Friedrichs, and Hans Lewy who introduced it in 1928. It is given by:Where C is the courant Continue reading
Refrigeration vs air conditioning systems
A major difference between refrigeration and air conditioning is the point of supply for the gases. The gas used in refrigeration was ammonia, air conditioning systems also uses ammonia, built-in chemicals and also air from the room or rooms being heated. Gases built into air conditioning units cool air that circulates through the unit then Continue reading
High performance computing for CFD
Computational fluid dynamics is a exponentially growing domain in the field of applied sciences. Experimental and analytical methods can only solve relatively simple problems. For instance, analytical methods are actually applied only to 1-dimensional and 2-dimensional problems, whereas experimental methods need lot of time and resources and there are feasibility issues. With the advent of Continue reading
HVAC System Design : Human Thermal Comfort
Human thermal comfort broadly refers how the occupants feel in side the conditioned space. Thermal comfort is difficult to measure since it depends on lot of parameters such as air velocity, metabolism, air temperature, individual experience and humidity.A cold sensation will be acceptable if the body is overheated, but will be uncomfortable when the body Continue reading
HVAC System Design : Insulation of Ducts for Energy Efficiency
Duct insulation is a major consideration because it ensures that the air flowing inside the duct will stay at the desired temperature and won’t leak out.When the air leaks out then there will be unnecessary energy loss, which means the system consumes more power to deliver the air at the required condition, which is not Continue reading
Use of Relaxation Factors in CFD Analysis
Field and Equation Under-relaxations:Under-relaxation is a fraction, often used in iterative methods to stabilize the linear solvers. Let’s assume a transport equation is solved for variable ϕ. As iterative method is being followed, the value of ϕ can get updated in subsequent iterations. At beginning of present iteration let’s denote the transport variable as ϕpi and after the Continue reading
Smoke extraction system design : smoke detectors
Smoke detector is a device which is used to detect the smoke when a fire occurs in the space where it is installed. There are two types of smoke detector i) ionization smoke detector ii) photoelectric smoke detector. The ionization smoke detector detect the fire more readily and swiftly. Photoelectric smoke detector detect the smoke Continue reading
HVAC system design : fan performance & selection
Fans play a major role in HVAC applications and affects the performance of HVAC systems. There are many types of fan used in HVAC systems e.g axial fan & centrifugal fan.Role Of Axial Fan:Axial fan are low cost fan which produce nominal pressure difference, so they are mostly used for small scale application with light Continue reading