Make-Up Air Performance CFD Study - CaptiveAire

2m ago
3 Views
0 Downloads
2.08 MB
9 Pages
Last View : 5d ago
Last Download : n/a
Upload by : Brenna Zink
Transcription

Make-Up Air Performance CFD StudyOctober 30, 2003

PURPOSECFD models are useful tools in visualizing airflow and temperature gradients and flow.This CFD (computational fluid dynamics) study was performed on an exhaust onlykitchen hood with a front, perforated make-up air system. The exhaust rate of thehood was held constant to determine how changes in velocity and temperature of themake-up air effect the kitchen.CFD MODEL PARAMETERSTwo CFD models were analyzed in this study. Model number 1 represents a make-upair system that introduces ambient outdoor air into the kitchen space. Model number 2represents a make-up air system with two plenums on the front of the hood. Theplenum closest to the hood (SP1) introduces 95 F ambient outdoor air into the spaceand the second plenum (SP2) introduces 72 F air conditioned air into the system.Exhaust Hood Parameters:Model 5424ND, 8 ft. Long16” Tall Baffle Filters6’6” Hanging Height2400 CFM Exhaust (300 CFM/Ft)6” Left and Right Overhang24” Front OverhangCooking Equipment Parameters:600 F Char broilers6 Burner, 96,000 BTU/Hr Each22.75” Deep x 32” Wide CookingSurface Each36” TallSupply Plenem Paramaters:8 ft. Long6” Tall12” WideRoom Parameters:72 F Ambient Temperature4 ft. Space on Both Sides of HoodNo Wall Opposite Hood WallThe following figures show the CFD model setups. Figures 1 and 3 illustrate the 3-Dmodels used for the analysis and figures 2 and 4 show the plan view of the hood,plenums and the cooking equipment, along with the general space layout.Figure 1. Model Number 1 – Ambient Outdoor Air Supply Plenum2

8’54”48”HOODPSP12”ROOMROOM WALLSFigure 2. Plan View of Model Number 1Figure 3. Model Number 2 – Ambient Outdoor Air Supply and AC Plenum3

8’54”48”HOODPSP (SP1)12”AC PLENUM (SP2)12”ROOMROOM WALLSFigure 4. Plan View of Model Number 2RESULTSThe CFD analysis results are illustrated on the following four pages. The first two pagesillustrate the results of the model 1 analysis and the last two pages illustrate the resultsof the model 2 analysis. Again, model number 1 represents a single supply plenum onthe front of the hood and model number 2 refers to an untempered supply plenum (SP1)along with an air conditioned plenum (SP2), both on the front of the hood.The first set of results for model number 1 show the supply air-stream being introducedat 85 F with a side-by-side comparison of 150 fpm and 200 fpm supply velocity. Thesecond set of results for model number 1 show the supply air-stream being introducedat 95 F with a side-by-side comparison of 150 fpm and 200 fpm supply velocity.The results for model number 2 on the third and fourth page show four scenarios. Allscenarios show untempered supply air (SP1) being delivered at 95 F, and conditionedsupply air (SP2) being delivered at 72 F. There are four cases for each of these sets ofresults showing combinations of 150 fpm and 200 fpm air velocities for each of theplenums.The CFD results are displayed as cross sections of temperature contours in the space( F), supply temperature pathlines ( F), velocity flow pathlines (fpm), and velocityprofiles (fpm). The results of model number 2 are also represented by an 82 Ftemperature contour showing the location of this constant temperature contour in thespace.4

Model Number 1: Supply Air Temperature 85 FSupply Velocity 150 fpmSupply Velocity 200 fpmTemperature Contour ( F)Temperature Contour ( F)Temperature Flow Pathlines ( F)Temperature Flow Pathlines ( F)Velocity Flow Pathlines (fpm)Velocity Flow Pathlines (fpm)Velocity Profile (fpm)Velocity Profile (fpm)5

Model Number 1: Supply Air Temperature 95 FSupply Velocity 150 fpmSupply Velocity 200 fpmTemperature Contour ( F)Temperature Contour ( F)Temperature Flow Pathlines ( F)Temperature Flow Pathlines ( F)Velocity Flow Pathlines (fpm)Velocity Flow Pathlines (fpm)Velocity Profile (fpm)Velocity Profile (fpm)6

Model Number 2: Temperature Contour ( F) SP1 95 F, SP2 72 FVelocity SP1 150 fpm, SP2 150 fpmVelocity SP1 150 fpm, SP2 200 fpmVelocity SP1 200 fpm, SP2 150 fpmVelocity SP1 200 fpm, SP2 200 fpmModel Number 2: Temperature Contour (82 F) SP1 95 F, SP2 72 FVelocity SP1 150 fpm, SP2 150 fpmVelocity SP1 150 fpm, SP2 200 fpmVelocity SP1 200 fpm, SP2 150 fpmVelocity SP1 200 fpm, SP2 200 fpm7

Model Number 2: Velocity Flow Pathlines ( F) SP1 95 F, SP2 72 FVelocity SP1 150 fpm, SP2 150 fpmVelocity SP1 150 fpm, SP2 200 fpmVelocity SP1 200 fpm, SP2 150 fpmVelocity SP1 200 fpm, SP2 200 fpmModel Number 2: Temperature Flow Pathlines ( F) SP1 95 F, SP2 72 FVelocity SP1 150 fpm, SP2 150 fpmVelocity SP1 150 fpm, SP2 200 fpmVelocity SP1 200 fpm, SP2 150 fpmVelocity SP1 200 fpm, SP2 200 fpm8

CONCLUSIONThe CFD analysis shows that kitchen comfort is dependent on the temperature andvelocity of the supply air. In reference to model number 1, these results show that byintroducing hot air (95 F) through the supply plenum at velocities greater than 150 fpm,the circulation of the supply air is promoted back into the exhaust hood. This is due tothe lower density of hot air. Hot air is less dense than cool air and thus has a tendencyto rise in the cooler kitchen environment. Hot air must have a greater discharge velocityto reach the lower edge of the exhaust hood and thus enter the hood instead of thekitchen.There are also noticeable results between 95 F supply air and 85 F supply air. Thecooler 85 F supply air stream results in a much tighter air circulation back into theexhaust hood with less supply air entering the kitchen. As a matter of fact, for modelnumber 1, the single supply plenum, the best results occur when the air is introduced at85 F and 200 fpm discharge velocity. Supply air can be felt by the cook at velocitiesgreater that 150 fpm. Given all of these parameters, the following table illustrates theideal supply plenum velocities at certain temperature ranges.Supply Air Temperature ( F) 5050 to 7575 to 8585 to 95 95Min. Air Velocity (fpm)0140160180200Max. Air Velocity (fpm)140160180200220Based on these results, heating the supply air in cold climates will allow the plenum tosupply more make-up air and cooling the make-up air in hot climates will allow for theplenum to discharge the air at the optimal velocity and have a minimal impact on thekitchen environment.In reference to model number 2, the kitchen environment is effected the least byintroducing the air conditioned air at a velocity equal to or greater than the untemperedsupply air. The best results in this analysis occur when the untempered air is deliveredat 150 fpm and the air conditioned air is delivered at 200 fpm. The air conditioned aircompletely pressurizes the untempered air toward the exhaust hood, thus preventingthe hot air from entering the kitchen. The hot air is forced into the exhaust hood to beexhausted and the cool, air conditioned air is free to mix with the air in the conditionedkitchen.9

at 150 fpm and the air conditioned air is delivered at 200 fpm. The air conditioned air completely pressurizes the untempered air toward the exhaust hood, thus preventing the hot air from entering the kitchen. The hot air is forced into the exhaust hood to be exhausted and the cool, air conditioned air is free to mix with the air in the conditioned

Related Documents:

refrigerator & freezer . service manual (cfd units) model: cfd-1rr . cfd-2rr . cfd-3rr . cfd-1ff . cfd-2ff . cfd-3ff . 1 table of contents

430 allocation to elianto cfd o&m 20,577.32 440 allocation to trillium west cfd o&m 27,267.00 450 allocation to west park cfd o&m 70,008.22 460 allocation to festival ranch cfd o&m 177,790.54 480 allocation to tartesso west cfd o&m 27,809.17 481 allocation to anthem sun valley cfd o&

A.2 Initial Interactive CFD Analysis Figure 2: Initial CFD. Our forward trained network provides a spatial CFD analysis prediction within a few seconds and is visualised in our CAD software. A.3 Thresholded and Modified CFD Analysis Figure 3: Threshold. The CFD is thresholded to localise on

performing CFD for the past 16 years and is familiar with most commercial CFD packages. Sean is the lead author for the tutorial and is responsible for the following sections: General Procedures for CFD Analyses Modeling Turbulence Example 3 - CFD Analysis

CFD Analysis Process 1. Formulate the Flow Problem 2. Model the Geometry 3. Model the Flow (Computational) Domain 4. Generate the Grid 5. Specify the Boundary Conditions 6. Specify the Initial Conditions 7. Set up the CFD Simulation 8. Conduct the CFD Simulation 9. Examine and Process the CFD Results 10. F

The CFD software used i s Fluent 5.5. Comparison between the predicted and simulated airflow rate is suggested as a validation method of the implemented CFD code, while the common practice is to compare CFD outputs to wind tunnel or full-scale . Both implemented CFD and Network models are briefly explained below. This followed by the .

Emphasis is on comparing CFD results, not comparison to experiment CFD Solvers: BCFD, CFD , GGNS Grids: JAXA (D), ANSA (E), VGRID (C) Turbulence Models: Spalart-Allmaras (SA), SA-QCR, SA-RC-QCR Principal results: Different CFD codes on same/similar meshes with same turbulence model generate similar results

This paper presents an open source computational fluid dynamics (CFD) study of air flow over a complex terrain. The open source C toolbox OpenFOAM has been used for the CFD analysis and the terrain considered is a scale model of Berlengas Island, which lies close to the Portuguese coast. In order to validate the CFD model,

CFD (Computational Fluid Dynamic) Model Comparison between Two Independent Models 1.ANSYS CFD was utilized by CCNY (CCNY City College of New York) 2.COMSOL CFD was employed by QRDC (QRDC is an R&D Company in Chaska, MN) 3.A virtual wind tunnel was constructed to examine the performance of an INVELOX system 4.The results are in agreement

developing experimental and computational databases for improving CC prediction capability. In general, CFD validation is defined by determining how well the CFD model predicts the performance and flow physics when used for its intended purposes.iv The level of CFD validation can be

CFD provides more detail and comprehensive information. Ability to study system under zero hazardous conditions at and beyond their normal performance limits. Power consumption of CFD is low as compared to a wind tunnel. CFD Analysis of temperature, velocity, and chemical concentration distribution can help an engineer to understand

CFD provides more detail and comprehensive information. Ability to study system under zero hazardous conditions at . and beyond their normal performance limits. Power consumption of CFD is low as compared to a wind . tunnel. CFD Analysis of temperature, velocity, and chemical . concentration distribution can help an engineer to

The first objective is to make comparison between the three CFD software which consists of ANSYS Fluent, Star-CCM and IESVE Mcroflo according to CFD . In terms of simulation results from the three baseline models, ANSYS Fluent is conclusively recommended for CFD modeling of complicated indoor fluid environment compared with Star-CCM

Precision Air 2355 air cart with Precision Disk 500 drill. Precision Air 2355 air cart with row crop tires attached to Nutri-Tiller 955. Precision Air 3555 air cart. Precision Air 4765 air cart. Precision Air 4585 air cart. Precision Air 4955 cart. THE LINEUP OF PRECISION AIR 5 SERIES AIR CARTS INCLUDES: Seven models with tank sizes ranging from

GPU Status Structural Mechanics Fluid Dynamics ANSYS Mechanical AFEA Abaqus/Standard (beta) LS-DYNA implicit Marc RADIOSS implicit PAM-CRASH implicit MD Nastran NX Nastran LS-DYNA Abaqus/Explicit 6 Electromagnetics AcuSolve Moldflow Culises (OpenFOAM) Particleworks CFD-ACE FloEFD Abaqus/CFD FLUENT/CFX STAR-CCM CFD LS-DYNA CFD Nexxim EMPro .

downstream of the grid. The CFD results and experimental data presented in the paper provide validation of the single-phase flow modeling methodology. Two-phase flow CFD models are being developed to investigate two-phase conditions in PWR fuel assemblies, and these can be presented at a future CFD Workshop. 1. INTRODUCTION

AUTODYN LS-Dyna CFD AcuSolve CFD CGNS Cobalt CONVERGE CFD FAST FIDAP FIRE Flow-3D GASP/GUST KIVA FEA ABAQUS I-DEAS LS-DYNA MP-Salsa MSC.Dytran MSC.Nastran MSC.Marc MSC.PATRAN NX Nastran PERMAS BIF/BOF RADIOSS NASTAR OpenFOAM Overflow PAM-FLOW Plot3D PowerFLOW RADIOSS-CFD

CFD and Process Engineering Conclusions CFD is well established and important for analysis of hydraulic components. There is growing appreciation that CFD can be a powerful tool for analysis of the imp

THE APPLICATION OF CFD TO BUILDING ANALYSIS AND DESIGN: A COMBINED APPROACH OF AN IMMERSIVE CASE STUDY AND WIND TUNNEL TESTING Daeung Kim ABSTRACT Computational Fluid Dynamics (CFD) can play an important role in building design. For all aspects and stages of building design, CFD

Topographical Anatomy A working knowledge of human anatomy is important for you as an EMT. By using the proper medical terms, you will be able to communicate correct information to medical professionals with the least possible confusion. At the same time, you need to be able to communicate with others who may or may not understand medical terms. Balancing these two facets is one of the most .