Kishor Khankari

• PhD
• CEO at AnSight LLC

Healthcare workers in post-anesthesia care units (PACU) are at risk of exposure to waste anesthetic gases (WAGs) released by patients in the recovery stage. The airflow patterns in the PACU play a crucial role in determining the spread and concentration of WAGs in the breathing zone of the occupants. A Computational Fluid Dynamics (CFD) study was c...

The primary objective of the hospital operating room (OR) ventilation system is to minimize surgical site infection due to airborne bacteria and to provide a comfortable environment for surgeons and other staff in the room. The key factor in reducing surgical site infection is to minimize the entrainment of airborne particulates from the non-steril...

The primary objective of hospital operating room (OR) ventilation systems is to minimize surgical site infection due to airborne contaminants and bacteria and to provide a comfortable environment for surgeons and other staff in the room. The key factor in reducing surgical site infection is to minimize the contamination of the sterile (clean) zone...

Ambient air is the primary heat rejection medium for the condenser coils of air-cooled chillers and dry coolers. Performance of air-cooled condensers can degrade under high ambient temperatures and windy conditions due to the recirculation of hot discharge plumes from the condenser fans into the chiller air intakes. Several factors including the wi...

Often high airflow rates or air change rates per hour (ACH) for laboratory spaces are specified to cover the risk of chemical exposure. This paper with the help of steady state isothermal Computational Fluid Dynamics (CFD) analysis investigates the impact of ACH and the location of a room return on the flow path of contaminants and resulting spatia...

Air is the primary carrier of heat, moisture, contaminants, and airborne contaminants in health-care facilities such as patient rooms, isolation rooms, and operating rooms. Therefore, the flow path of supply air plays an important role in determining the air velocities, air temperatures, concentration of contaminants, and flow path of airborne path...

A Computational Fluid Dynamics (CFD) analyses of a bank air cooled chillers adjacent to a 3-story building indicate with increase in wind speed the intake air temperature at chiller intakes increase due to increase in the recirculation of hot discharge plumes. At lower wind speeds the discharge plumes tend to move vertically upward away from the ch...

This paper with the help of Computational Fluid Dynamics (CFD) analysis compares the cooling performance of a traditional all air system with the radiant cooling systems for a typical perimeter office. The effect of supply airflow rate on the cooling performance of both radiant floor and radiant ceiling systems is evaluated. The cooling performance...

A Computational Fluid Dynamics analysis of a bank air cooled chillers adjacent to a 3-story building indicates an increase in the wind speed increases recirculation of discharge plumes into the chiller intakes resulting in higher intake air temperatures. At lower wind speeds the discharge plumes tend to move vertically upward away from the chillers...

Virtual patient room was created with the help of CFD models to evaluate two different design configurations of active chilled beams to obtain in-depth insights regarding airflow patterns, temperature distribution, thermal comfort of occupants, and — critically — on the probable path of airborne particles (pathogens) in a patient room. These analys...

Air cooled chillers are becoming a primary choice for heat rejection in the regions of short supply of water. The performance of the air cooled condensers/chillers can degrade under high ambient temperature and windy conditions. Several factors including the wind speed, wind direction, spacing between the chillers, and distance from the adjacent bu...

A virtual patient room was created with the help of CFD to evaluate the impact of return-grill location. The analyses provided valuable insight into airflow patterns, temperature distribution, thermal comfort, and, perhaps most importantly, the probable path of airborne particles (pathogens). The traditional practice of placing the return grill nea...

Active chilled beams can provide energy efficient operation due to their hydronic sensible cooling, lower fan power requirements, and reduced reheat during low load or part load cooling conditions. Revision to ASHRAE Standard 170-2008 which allows recirculated air to be part of the total minimum air change rate requirements makes possible to employ...

Mini-environment cleanrooms are commonly employed in the semi-conductor and pharmaceutical industries to create isolated spaces within a cleanroom to provide better control on the cleanliness and operation of the processes. Mini-environments isolate products and operators from each other to avoid any cross contamination. The required airflow to mai...

An exhaust fan assembly is provided for expelling contaminated air from a building. The assembly includes a plenum, a fan assembly attached to the plenum, and a windband mounted on top of the fan assembly. The fan assembly is constructed of cylindrical outer and inner walls which define a bearing chamber and surrounding annular space. A fan driven...

Management of both cold and hot airflow paths is crucial for energy efficient cooling of servers in data centers. Containment of cold and hot aisles can provide separation between these two streams; however, air leakages from these systems can affect their effectiveness. This paper with the help of a virtual test setup developed using Computational...

A virtual patient room was created with the help of CFD models to evaluate the effect of various HVAC design configurations for two different locations of the return grill. These analyses provided valuable insights into airflow patterns, temperature distribution, thermal comfort of occupants, and(very importantly) the probable path of airborne part...

A virtual patient room was created with the help of CFD models to evaluate the effect of various HVAC design configurations for two different locations of the return grill. These analyses provided valuable insights into airflow patterns, temperature distribution, thermal comfort of occupants, and (very importantly) the probable path of airborne par...

The distribution of supply air determines the resulting air velocities, temperatures, and concentration of contaminants in a patient room. This in turn determines thermal comfort and potential for transmission of airborne infectious pathogens in a patient room. Several inter related factors can affect the performance of air distribution systems inc...

Stratified air ventilation systems such as displacement ventilation can provide better indoor air quality with enhanced ventilation effectiveness compared to the traditional overhead mixing systems. In the case of displacement ventilation systems the higher supply air temperatures combined with the low supply airflow rates can also provide higher e...

During power outages servers in the data centers are generally powered by uninterruptible power supplies (UPS). At the same time the sources for active cooling such as CRACs, CRAHs, and chillers stop operating for a period until powered by alternate power sources. During this period servers continue to generate heat without any active cooling. This...

Rack enclosures are a crucial link between data center airhandling units and servers. Design of rack enclosures can impact the fan performance, and therefore, cooling performance of servers. Careful consideration should be given before selecting the rack enclosures for a certain data center. Just following the best practices for the design and layo...

Cylindrical (carousel) and spherical dome designs for the Large Synoptic Survey Telescope (LSST) were analyzed for air flow characteristics using computational fluid dynamic models. The primary objective was to determine the level of dome flushing achieved with natural ventilation and representative site wind conditions. The domes were 30 meters in...

Today's critical high-density electronic equipment environments need adequate equipment (rack) cooling without excessive energy usage. This paper presents a methodology for optimizing the rack cooling effectiveness and HVAC cooling costs in telecom and data centers. Since raised-floor air distribution is the most common way of cooling data centers,...

In this study, computational fluid dynamics (CFD) models are used to evaluate how ceiling height affects the overall performance of the air distribution system within a data center environment. First, an underfloor air delivery system is examined while keeping all operational parameters constant and varying only the clear space height. Then, the pe...

This paper illustrates the use of numerical simulation models for evaluating the performance of a moving bed dryer. A finite-volume method is employed in developing a steady state, two-dimensional numerical model for a double-deck conveyor dryer. Using this numerical model, variations in the product moisture content and temperature along the length...

Variations in ambient temperatures cause safe moisture contents of stored grain to become unsafe due to migration or redistribution of moisture within storage. This study uses a previously developed generalized numerical model of the moisture migration process, which can be used to predict the temperature, moisture, and natural convection air-flow...

Thermal gradients that develop due to the seasonal variations in ambient temperatures cause natural convection air-flow and migration of moisture within bulk grain. In this article, a mathematical model of moisture migration is developed by reflecting the change in air moisture on the grain moisture through the sorption isotherm. Thus, the effect o...

Seasonal variations in ambient temperatures can cause safe moisture contents of stored grain to become unsafe due to migration or redistribution of moisture within the storage. Such migration of moisture generally occurs due to thermal gradients in the stored grain and depends on various factors related to the grain quality, bin size, and local cli...

During power outage servers in the data centers are powered by uninterrupted power supply (UPS). At the same time, the cooling system components such as CRACs, AHUs, and chillers stop operating for a short period until powered by alternate power sources. During this period servers continue generating heat in the data center room without active cool...