@article {2591, title = {A framework for simulation-based real-time whole building performance assessment}, journal = {Building and Environment}, volume = {54}, year = {2012}, month = {08/2012}, pages = {100-108}, chapter = {100}, abstract = {

Most commercial buildings do not perform as well in practice as intended by the design and their performances often deteriorate over time. Reasons include faulty construction, malfunctioning equipment, incorrectly configured control systems and inappropriate operating procedures. One approach to addressing this problems is to compare the predictions of an energy simulation model of the building to the measured performance and analyze significant differences to infer the presence and location of faults. This paper presents a framework that allows a comparison of building actual performance and expected performance in real time. The realization of the framework utilized the EnergyPlus, the Building Controls Virtual Test Bed (BCVTB) and the Energy Management and Control System (EMCS) was developed. An EnergyPlus model that represents expected performance of a building runs in real time and reports the predicted building performance at each time step. The BCVTB is used as the software platform to acquire relevant inputs from the EMCS through a BACnet interface and send them to the EnergyPlus and to a database for archiving. A proof-of-concept demonstration is also presented.

}, keywords = {building controls virtual test bed, building performance, energy modeling, energyplus, real-time building simulation}, issn = {0360-1323}, author = {Xiufeng Pang and Michael Wetter and Prajesh Bhattacharya and Philip Haves} } @proceedings {2785, title = {BACnet and Analog/Digital Interfaces of the Building Controls Virtual Test Bed}, year = {2011}, month = {11/2011}, pages = {p. 294-301}, address = {Sydney, Australia}, author = {Thierry Stephane Nouidui and Michael Wetter and Zhengwei Li and Xiufeng Pang and Prajesh Bhattacharya and Philip Haves} } @article {3181, title = {BacNet and Analog/Digital Interfaces of the Building Controls Virtual Testbed}, year = {2011}, month = {11/2011}, abstract = {

This paper gives an overview of recent developments in the Building Controls Virtual Test Bed (BCVTB), a framework for co-simulation and hardware-in-the-loop.

First, a general overview of the BCVTB is presented. Second, we describe the BACnet interface, a link which has been implemented to couple BACnet devices to the BCVTB. We present a case study where the interface was used to couple a whole building simulation program to a building control system to assess in real-time the performance of a real building. Third, we present the ADInterfaceMCC, an analog/digital interface that allows a USB-based analog/digital converter to be linked to the BCVTB. In a case study, we show how the link was used to couple the analog/digital converter to a building simulation model for local loop control.

}, author = {Philip Haves and Prajesh Bhattacharya and Thierry Stephane Nouidui and Michael Wetter and Zhengwei Li and Xiufeng Pang} } @proceedings {2787, title = {Real-time Building Energy Simulation using EnergyPlus and the Building Controls Virtual Test Bed}, year = {2011}, month = {11/2011}, pages = {p. 2890-2896}, address = {Sydney, Australia}, abstract = {

Most commercial buildings do not perform as well in practice as intended by the design and their performances often deteriorate over time. Reasons include faulty construction, malfunctioning equipment, incorrectly configured control systems and inappropriate operating procedures (Haves et al., 2001, Lee et al., 2007). To address this problem, the paper presents a simulation-based whole building performance monitoring tool that allows a comparison of building actual performance and expected performance in real time. The tool continuously acquires relevant building model input variables from existing Energy Management and Control System (EMCS). It then reports expected energy consumption as simulated of EnergyPlus. The Building Control Virtual Test Bed (BCVTB) is used as the software platform to provide data linkage between the EMCS, an EnergyPlus model, and a database. This paper describes the integrated real-time simulation environment. A proof-of-concept demonstration is also presented in the paper.

}, author = {Xiufeng Pang and Prajesh Bhattacharya and Zheng O{\textquoteright}Neill and Philip Haves and Michael Wetter and Trevor Bailey} } @proceedings {393, title = {Automated Continuous Commissioning of Commercial Buildings}, year = {2010}, month = {11/2010}, address = {Washington, D.C.}, author = {Trevor Bailey and Zheng O{\textquoteright}Neill and Madhusudana Shashanka and Prajesh Bhattacharya and Philip Haves and Xiufeng Pang} } @proceedings {394, title = {{\textquotedblleft}The Monitoring,{\textquotedblright} Panel: Chill-Off}, year = {2009}, month = {10/2009}, address = {Sunnyvale, CA}, author = {Dean Nelson and Brian Day and Geoffrey C. Bell and Prajesh Bhattacharya and Mike Ryan} } @proceedings {395, title = {Convergence of IT and Facilities Real-Time and Historic Data Leads to Data Center Efficiency}, year = {2008}, month = {05/2008}, address = {Orlando, FL}, author = {Prajesh Bhattacharya} } @article {377, title = {Unlocking Historical Data in Critical IT}, journal = {Data Center Dynamics Focus}, year = {2008}, month = {12/2008}, author = {Prajesh Bhattacharya} } @conference {380, title = {Coverage Problem for Sensors Embedded in Temperature Sensitive Environments}, booktitle = {IEEE Infocom, 2007}, year = {2007}, month = {5/2007}, address = {Anchorage, AL}, author = {Arunabha Sen and Nibedita Das and Ling Zhou and Bao Hong Shen and Sudheendra Murthy and Prajesh Bhattacharya} } @article {379, title = {Brownian Motion Based Convective- Conductive Model for the Effective Thermal Conductivity of Nanofluids}, journal = {Journal of Heat Transfer}, volume = {128}, year = {2006}, pages = {588-595}, chapter = {588}, author = {Ravi S. Prasher and Prajesh Bhattacharya and Patrick E. Phelan} } @proceedings {396, title = {Carbon Nanotube (CNT)-Centric Thermal Management of Future High Power Microprocessors}, year = {2006}, month = {03/2006}, address = {Atlanta, GA}, author = {Prajesh Bhattacharya and Wei, X. and Andrei G. Fedorov and Yogendra K. Joshi and Navdeep Bajwa and Anyuan Cao and Pulickel Ajayan} } @article {378, title = {Characterization of the Temperature Oscillation Technique to Measure the Thermal Conductivity of Fluids}, journal = {International Journal of Heat and Mass Transfer}, volume = {49}, year = {2006}, month = {08/2006}, pages = {2950-2956}, chapter = {2950}, abstract = {

The temperature oscillation technique to measure the thermal diffusivity of a fluid consists of filling a cylindrical volume with the fluid, applying an oscillating temperature boundary condition at the two ends of the cylinder, measuring the amplitude and phase of the temperature oscillation at any point inside the cylinder, and finally calculating the fluid thermal diffusivity from the amplitude and phase values of the temperature oscillations at the ends and at the point inside the cylinder. Although this experimental technique was introduced by Santucci and co-workers nearly two decades ago, its application is still limited, perhaps because of the perceived difficulties in obtaining accurate results. Here, we attempt to clarify this approach by first estimating the maximum size of the liquid{\textquoteright}s cylindrical volume, performing a systematic series of experiments to find the allowable amplitude and frequency of the imposed temperature oscillations, and then validating our experimental setup and the characterization method by measuring the thermal conductivity of pure water at different temperatures and comparing our results with previously published work.

}, keywords = {Temperature oscillation technique, Thermal conductivity, thermal diffusivity}, url = {http://www.sciencedirect.com/science/article/pii/S001793100600144X}, author = {Prajesh Bhattacharya and S. Nara and P. Vijayan and Tang, T. and W. Lai and Patrick E. Phelan and Ravi S. Prasher and David W. Song and J. Wang} } @article {378, title = {Characterization of the Temperature Oscillation Technique to Measure the Thermal Conductivity of Fluids}, journal = {International Journal of Heat and Mass Transfer}, volume = {49}, year = {2006}, month = {08/2006}, pages = {2950-2956}, chapter = {2950}, abstract = {

The temperature oscillation technique to measure the thermal diffusivity of a fluid consists of filling a cylindrical volume with the fluid, applying an oscillating temperature boundary condition at the two ends of the cylinder, measuring the amplitude and phase of the temperature oscillation at any point inside the cylinder, and finally calculating the fluid thermal diffusivity from the amplitude and phase values of the temperature oscillations at the ends and at the point inside the cylinder. Although this experimental technique was introduced by Santucci and co-workers nearly two decades ago, its application is still limited, perhaps because of the perceived difficulties in obtaining accurate results. Here, we attempt to clarify this approach by first estimating the maximum size of the liquid{\textquoteright}s cylindrical volume, performing a systematic series of experiments to find the allowable amplitude and frequency of the imposed temperature oscillations, and then validating our experimental setup and the characterization method by measuring the thermal conductivity of pure water at different temperatures and comparing our results with previously published work.

}, keywords = {Temperature oscillation technique, Thermal conductivity, thermal diffusivity}, url = {http://www.sciencedirect.com/science/article/pii/S001793100600144X}, author = {Prajesh Bhattacharya and S. Nara and P. Vijayan and Tang, T. and W. Lai and Patrick E. Phelan and Ravi S. Prasher and David W. Song and J. Wang} } @article {381, title = {Effect of Aggregation Kinetics on the Thermal Conductivity of Nanoscale Colloidal Solutions (Nanofluids)}, journal = {Nanoletters}, volume = {6}, year = {2006}, pages = {1529-1534}, chapter = {1529}, author = {Ravi S. Prasher and Prajesh Bhattacharya and Patrick E. Phelan} } @conference {382, title = {Effect of Coloidal Chemistry on the Thermal Conductivity of Nanofluids}, booktitle = {International Mechanical Engineering Congress \& Exposition}, year = {2006}, month = {11/2006}, address = {Chicago, IL}, author = {Ravi S. Prasher and Prajesh Bhattacharya and Patrick E. Phelan} } @article {383, title = {Enhanced Mass Transport in Nanofluids}, journal = {Nanoletters}, volume = {6}, year = {2006}, month = {03/2006}, pages = {419-423}, chapter = {419}, abstract = {

Thermal conductivity enhancement in nanofluids, which are liquids containing suspended nanoparticles, has been attributed to localized convection arising from the nanoparticles{\textquoteright} Brownian motion. Because convection and mass transfer are similar processes, the objective here is to visualize dye diffusion in nanofluids. It is observed that dye diffuses faster in nanofluids compared to that in water, with a peak enhancement at a nanoparticle volume fraction, φ, of 0.5\%. A possible change in the slope of thermal conductivity enhancement at that same φ signifies that convection becomes less important at higher φ. The enhanced mass transfer in nanofluids can be utilized to improve diffusion in microfluidic devices.

}, doi = {10.1021/nl0522532}, author = {S. Krishnamurthy and Prajesh Bhattacharya and Patrick E. Phelan and Ravi S. Prasher} } @proceedings {397, title = {Computational Analysis of the Colloidal Stability of Nanofluids}, year = {2005}, month = {11/2005}, address = {Orlando, FL}, author = {Prajesh Bhattacharya and Patrick E. Phelan and Ravi S. Prasher} } @conference {388, title = {Effect of Particle Material on the Static Thermal Conductivity of Nanofluids}, booktitle = {Heat Transfer Conference}, year = {2005}, month = {07/2005}, address = {San Francisco, CA}, author = {P. Vijayan and Prajesh Bhattacharya and S. Nara and W. Lai and Patrick E. Phelan and Ravi S. Prasher and David W. Song and J. Wang} } @conference {385, title = {Experimental Determination of the Effect of Varying Base Fluid and Temperature on the Static Thermal Conductivity of Nanofluids}, booktitle = {ASME International Mechanical Engineering Congress and Exposition, November 5-11, 2005}, year = {2005}, month = {11/2005}, publisher = {ASME}, organization = {ASME}, address = {Orlando, FL}, abstract = {

The heat transfer abilities of fluids can be improved by adding small particles of sizes of the order of nanometers. Recently a lot of research has been done in evaluating the thermal conductivity of nanofluids using various nanoparticles. In our present work we address this issue by conducting a series of experiments to determine the effective thermal conductivity of alumina-nanofluids by varying the base fluid with water and antifreeze liquids like ethylene glycol and propylene glycol. Temperature oscillation method is used to find the thermal conductivity of the nanofluid. The results show the thermal conductivity enhancement of nanofluids depends on viscosity of the base fluid. Finally the results are validated with a recently proposed theoretical model.

}, isbn = {0-7918-4221-5}, doi = {10.1115/IMECE2005-81494}, author = {S. Nara and Prajesh Bhattacharya and P. Vijayan and W. Lai and W. Rosenthal and Patrick E. Phelan and Ravi S. Prasher and David W. Song and Jinlin Wang} } @article {387, title = {Thermal Conductivity of Nanoscale Colloidal Solutions (Nanofluids)}, journal = {Physical Review Letters}, volume = {94}, year = {2005}, chapter = {025901-1}, author = {Ravi S. Prasher and Prajesh Bhattacharya and Patrick E. Phelan} } @article {386, title = {Brownian Dynamics Simulation to Determine the Effective Thermal Conductivity of Nanofluids}, journal = {Journal of Applied Physics}, volume = {95}, year = {2004}, month = {06/2004}, pages = {6492{\textendash}6494}, chapter = {6492}, abstract = {

A nanofluid is a fluid containing suspended solid particles, with sizes on the order of nanometers. Normally, nanofluids have higher thermal conductivities than their base fluids. Therefore, it is of interest to predict the effective thermal conductivity of such a nanofluid under different conditions, especially since only limited experimental data are available. We have developed a technique to compute the effective thermal conductivity of a nanofluid using Brownian dynamics simulation, which has the advantage of being computationally less expensive than molecular dynamics, and have coupled that with the equilibrium Green-Kubo method. By comparing the results of our calculation with the available experimental data, we show that our technique predicts the thermal conductivity of nanofluids to a good level of accuracy.

}, keywords = {complex fluids, Disperse systems, Thermal conduction in nonmetallic liquids}, doi = {10.1063/1.1736319}, author = {Prajesh Bhattacharya and Saha, S.K. and Ajay K. Yadav and Patrick E. Phelan and Ravi S. Prasher} } @conference {389, title = {Determining the Effective Viscosity of a Nanofluid Using Brownian Dynamics Simulation}, booktitle = {1st International Symposium on Micro \& Nano Technology}, year = {2004}, month = {03/2004}, address = {Honolulu, HI}, author = {Prajesh Bhattacharya and Patrick E. Phelan and Ravi S. Prasher} } @conference {390, title = {Evaluation of the Temperature Oscillation Technique to Calculate Thermal Conductivity of Water and Systematic Measurement of the Thermal Conductivity of Aluminum Oxide {\textendash} Water Nanofluiids}, booktitle = {International Mechanical Engineering Congress \& Exposition,}, year = {2004}, month = {11/2004}, address = {Anaheim, CA}, author = {Prajesh Bhattacharya and P. Vijayan and Tang, T. and S. Nara and Patrick E. Phelan and Ravi S. Prasher and J. Wang and David W. Song} } @proceedings {398, title = {Numerical Tools For Particle- Fluid Interactions}, year = {2004}, month = {02/2004}, author = {R. Calhoun and Patrick E. Phelan and Ajay K. Yadav and Prajesh Bhattacharya} } @conference {391, title = {Determining the Effective Thermal Conductivity of a Nanofluid Using Brownian Dynamics Simulation}, booktitle = {National Heat Transfer Conference}, year = {2003}, month = {07/2003}, address = {Las Vegas, NV}, author = {Prajesh Bhattacharya and Saha, S.K. and Ajay K. Yadav and Patrick E. Phelan and Ravi S. Prasher} } @proceedings {399, title = {Modeling the Behavior of F1-ATPase Biomolecular Motors Using Brownian Dynamics Simulation}, year = {2002}, month = {09/2002}, address = {Scottsdale, AZ}, author = {Prajesh Bhattacharya and Patrick E. Phelan} } @conference {392, title = {Understanding the Behavior of an F1-ATPase Biomolecular Motor Using Brownian Dynamics Simulation}, booktitle = {US-Japan Nanotherm Seminar: Nanoscale Thermal Science and Engineering}, year = {2002}, month = {06/2002}, address = {Berkeley, CA}, author = {Prajesh Bhattacharya and Patrick E. Phelan} } @article {384, title = {Nanofluids for Heat Transfer Applications}, journal = {Annual Review of Heat Transfer}, volume = {14}, year = {1995}, pages = {255-275}, chapter = {255}, author = {Patrick E. Phelan and Ravi S. Prasher and Prajesh Bhattacharya} }