Numerical Modeling and Simulation of Fluid Flow and Heat Transfer in Engineering Applications Son H. Ho, Ph.D. Center for Advanced Turbines and Energy Research University of Central Florida Room 288, Building ENG I, University of Central Florida – February 24, 2009

Agenda 1.Zero Boil-Off (ZBO) Storage of Cryogenic Liquid Hydrogen (LH2) 2.HVAC&R Indoor Spaces – Thermal Comfort and Contaminant Removal 3.Modeling and Design Micropump 4.Portable Blood Cooling System 5.Other Works

Governing Equations (Incompressible & Constant Property Fluid Flow) Conservation of mass: Conservation of momentum: Conservation of energy: Conservation of mass for water vapor: Conservation of mass for contaminant gas:

LH2 in Space & Automotive Applications Centaur upper stage – liquid hydrogen/liquid Oxygen propelled rocket Transport of liquid hydrogen used in space applications. Hydrogen tank in a car’s trunk. Hydrogen Hummer (converted by Intergalactic Hydrogen). Shelby Cobras (Hydrogen Car Co.)

Cryogenic Liquid Hydrogen Storage Tank with Lateral Pump-Nozzle Unit Fluid: LH2 3-D Model Steady-State Analysis

3-D Model and Dimensions

3-D Hexahedral-Element Mesh

Distribution of Velocity, m/s Streamlines Speed Velocity vector and speed

Distribution of Temperature, K

HVAC&R Applications Refrigerated Warehouse Hospital Operating Room

Refrigerated Warehouse with Ceiling Type Cooling Unit Fluid: Air Two- and Three-Dimensional Models Steady-State Analysis

2-D and 3-D Models

2-D and 3-D Mesh Quadrilateral Elements Hexahedral Elements

Streamlines and Speed, m/sTemperature, °C 2-D Simulation Results

3-D Simulation Results (a) Streamlines. (b) Speed, m/s. (c) Pressure, Pa.(d) Temperature, °C.

Thermal Comfort Enhancement using Ceiling Fan in Air-Conditioned Room Fluid: Air Mixture (dry air + water vapor) Two-Dimensional Model Steady-State Analysis

2-D Model of Air-Conditioned Room with Ceiling Fan

2-D Simulation Results Streamlines and speed, m/s. Temperature, °C. Streamlines and speed, m/s. Temperature, °C. (a) Ceiling fan not running(b) Ceiling fan running

3-D Simulation Results

PMV Distributions (a) Ceiling fan not running(b) Ceiling fan running

Thermal Comfort and Contaminant Removal in Hospital Operating Room Fluid: Air Mixture (dry air + water vapor + contaminant gas) Three-Dimensional Model Steady-State Analysis

Three-Dimensional Model

3-D Hexahedral-Element Mesh

3-D Simulation Results StreamlinesSpeed, m/s Temperature, °CContaminant concentration, mg/kg air

Journal 1.Ho, S. H., Rosario, L., and Rahman, M. M., “Three-dimensional analysis for hospital operating room thermal comfort and contaminant removal,” Applied Thermal Engineering (In press, available online 13 November 2008). 2.Ho, S. H., Rosario, L., and Rahman, M. M., “Thermal comfort enhancement by using a ceiling fan,” Applied Thermal Engineering (In press, available online 25 July 2008). 3.Ho, S. H. and Rahman, M. M., “Nozzle injection displacement mixing in a zero boil-off hydrogen storage tank,” Int. J. Hydrogen Energy 33 (2) (2008) pp Ho, S. H. and Rahman, M. M., “Three-dimensional analysis for liquid hydrogen in a cryogenic storage tank with heat pipe-pump system,” Cryogenics 48 (1-2) (2008), pp Kaw, A. K. and Ho, S. H., “On introducing approximate solution methods in theory of elasticity,” Comput. Appl. Eng. Educ. 14 (2) (2006), pp Conference 1.Meckler, M. and Ho, S. H., “Integrate CHP to improve overall corn ethanol economics,” Proceedings of 2008 ASME International Mechanical Engineering Congress and Exposition, IMECE , Nov. 2008, Boston, Massachusetts. 2.Ho, S. H. and Rahman, M. M., “Transient thermal analysis of cryogenic liquid hydrogen tank with active circulation,” Proceedings of Energy Sustainability 2007, ES , Jun. 2007, Long Beach, California. 3.Ho, S. H., Rosario, L. and Rahman, M. M., “Numerical analysis of thermal behavior in a refrigerated warehouse,” Proceedings of 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE , Nov. 2006, Chicago, Illinois. 4.Ho, S. H. and Rahman, M. M., “Zero boil-off cryogenic liquid hydrogen storage tank with axial cold-spray system,” Proceedings of 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE , Nov. 2006, Chicago, Illinois. 5.Rahman, M. M., Ho, S. H., and Rosario, L., “Review and some research results on hydrogen liquefaction and storage,” Proceedings of the International Conference on Mechanical Engineering 2005, ICME2005, Dec. 2005, Dhaka, Bangladesh. 6.Ho, S. H., Rosario L., and Rahman, M. M., “Effect of using ceiling fan on human thermal comfort in air-conditioned space,” Proceedings of AIAA 3rd International Energy Conversion Engineering Conference and Exhibit (IECEC), AIAA , Aug. 2005, San Francisco, California. 7.Ho, S. H. and Rahman, M. M., “Three-dimensional analysis of liquid hydrogen cryogenic storage tank,” Proceedings of AIAA 3rd International Energy Conversion Engineering Conference and Exhibit (IECEC), AIAA , Aug. 2005, San Francisco, California. 8.Ho, S.H., Rosario, L., and Rahman, M.M., “Analysis of thermal comfort and contaminant removal in an office room with underfloor air distribution system,” Proceedings of 2005 ASME Summer Heat Transfer Conference, HT , Jul. 2005, San Francisco, California. 9.Rahman, M. M. and Ho, S. H., “Zero boil-off cryogenic storage of hydrogen,” NHA 2005 Proceedings of Hydrogen Conference, Mar. 2005, Washington, D.C. 10.Ho, S. H., Rosario, L., and Rahman, M. M., “Predictions of relative humidity and temperature in an operating room,” Proceedings of 2004 ASME International Mechanical Engineering Congress and Exposition, IMECE , Nov. 2004, Anaheim, California. Publications

Mesh Development for Indoor Environmental CFD Modeling

Geometry Decomposition and Meshing for 2-D Model S = 0.1 m, H = 0.05 m, N = 3 and R = square elements (58%) in total 2570 quadrilateral elements.

Geometry Decomposition for 3-D Model (1)

Geometry Decomposition for 3-D Model (2)

Meshing 3-D Model using Encapsulation Techniques (1)

Meshing 3-D Model using Encapsulation Techniques (2)

3-D Mesh: Layers of Refined Element Mesh on Fluid-Solid Interfaces

3-D Mesh: Cubical Elements (62%) in total of Hexahedral Elements

Modeling and Design Micropump

Diaphragm micropump with passive check-valves Destination Inlet valve Outlet valve Pump chamber p1p1 p2p2 ss 1122 dd Diaphragm Source 1 22 Valve discs z V dead p2*p2* p1*p1* p(t)p(t) p(t) ΔVΔV

Pump chamber: mathematical model

Pump chamber: Simulink model

Pump chamber: simulation results

Thermopneumatic micropump

Diaphragm deflection

Temperature–deflection relationship

Temperature vs. deflection

Actuation chamber: math. model

Actuation chamber: Simulink model

Actuation chamber: simulation results Experimental data

Thermopneumatic micropump: Simulink model

Thermopneumatic micropump: simulation results

Portable Blood Cooling System

Simulation Results

Cooling Cylinder: math. model

Cooling Cylinder (Isothermal case): Simulink model

Other Works

Applied Mechanics Lab (Vietnam, 1995 – 2001)

8051-based Application (2003) Click to play video clip

Thank You!