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  • HeatEx SimScene
    lasting specifically for a time during which fluid 1 fills the volume available to it twice for that is the meaning of the somewhat cryptic formula appearing on the screen Other parameters which may be set are accessed by clicking on one of the other boxes on the left of the screen b Geometry Clicking on the geometry box elicits the following menu the significance of which is self explanatory c Material properties Clicking on the material properties box in its turn elicits the following image About this the following remarks are in order The second from top box on the right is a two item pull down menu which when the non default yes choice is made sets the properties to non dimensional unity values for simplicity Otherwise those from the lower boxes are used The lowest four boxes on the right shown above allow the influences of varying properties to be investigated to some extent Specifically the enthalpy versus temperature relation of fluid 2 is supposed to have the three part form shown below The menu allows the co ordinates of points B and C to be varied corresponding to the differing specific heats of the liquid and vapour phases and to their latent heat of vaporisation to be reflected Were C to be placed vertically above B the enthalpy temperature relation would correspond to that of a pure substance Mixtures on the other hand for example water and alcohol will have enthalpy temperature relations of which the transitions between the three straight lines will be rounded rather than abrupt But the HeatEx SimScene even in its present simple form enable the main effects of real mixttres to be investigated d Initial conditions Clicking on the left hand side initial conditions box reveals the following menu For steady state simulations initial conditions are no more than initial guesses they do not influence the final solution They do however have significance for and therefore influence on the solution of time dependent simulations as will be seen in section 2 2 below e Boundary conditions Clicking on the boundary conditions box for example elicits the following image Here are more parameters which may be set by typing over existing entries in the white boxes on the right hand side The meanings of the items occupying the first four boxes are self explanatory and the fifth the number of transfer units is the means by which the overall heat transfer coefficient U W m 2 degC is specified The two lower boxes require more explanation Analytical expressions for heat exchanger effectiveness are based on the presumption that the overall heat transfer coefficient is uniform i e that its value is the same at all points in the heat exchanger The presumption is often far from the truth because thermophysical properties vary with temperature and the relative velocity of fluid and wall which strongly influences the convective component of the coefficient varies greatly with position Therefore HeatEx has been supplied with means for demonstrating that its numerical methods are subject to no such restriction Specifically if either or both of the numbers in the lower boxes are set to a non zero value the overall heat transfer coefficient will be computed from the formula indicated No particular physical process is implied thereby but users can gain insight into the effects by varying the numbers Clicking on any of the three boxes on the left hand side of the screen leads to other menus in which other groups of parameters may be set f Output Clicking on the output box elicits the following image enabling miscellaneous output related settings to be made g Numerical Of the image elicited by clicking on the numerical button as shown below there is little to say The numerical settings concern grid size and relaxation factors the nature of which is known to most users of numerical simulation packages The third item namely the number of time steps has an influence only if the second menu box of the general menu has been filled with a value in excess of zero i Concluding remarks regarding settings which can be made via menus About the settings which can be made via menus the user may reasonably ask Why this and not that The answer is Because the SimScene creator guessed perhaps wrongly what you would like to be able to adjust It should therefore be recognised that it is easy to make any simulation influencing setting menu adjustable This is not the place to explain how to do so but some insight will be provided in section 3 below 2 2 Running the flow simulating calculation When the user has made his choices clicking on the Run the simulation button causes the PHOENICS Satellite and Earth modules to be run in sequence in the directory phoenics d sapps HeatEx working No user intervention is needed 2 3 Inspecting the results Inspection of the results of the calculation is facilitated by the screen which appears after the computation is completed thus This is the inforout file which has been placed by EARTH in the working directory The heat exchanger effectiveness is among the items printed there Another file of interest is the result file that can be loaded via the Open file button The user may immediately explore its content aided by the Find button If graphical display is preferred it may be elicited by clicking on the button whereupon in the present case PHOTON is launched which reacts automatically to the macro u which has been automatically written in the working directory A typical image is the following wherein the left hand contours represent the distribution of heat flux to the cooler fluid entering from the left while the right hand ones represent the equal flux leaving the hotter fluid entering from below on the right The two leaky baffle case is the one in question A different picture will appear if the process is transient as shown by

    Original URL path: http://www.cham.co.uk/phoenics/d_sapps/heatex/docs/descr_en.htm (2016-02-15)
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  • have no effect on the case set up When importing a custom CAD geometry it is highly likely that the model will include wheels and thus in such a case users should set the use and display wheels parameter to false Provided wheels are being added to the case the next four parameters govern the wheel diameter and width These values can be adjusted by simply entering the desired value in the appropriate white box The next two parameters front axle position from defaults and rear axle position from default govern the front and rear axle positions relative to their default locations The default wheel positions are set automatically Entering a positive value for either of these parameters will move the appropriate wheelset towards the front of the car and a negative value will move the appropriate wheelset towards the rear of the car The final two parameters front axle extension from default and rear axle extension from default govern the front and rear axle lengths This determines how far apart the wheels are By default the case has been set up to place the wheels 5mm away from the car body in accordance with the F1 in Schools rules Increasing these parameters will place the wheels further away from the car body and decreasing them will bring the wheels closer together NOTE The wheel dimensions for the case are also bound by the competition technical regulations The F1 VWT attempts to inform the user of any rule contraventions but to ensure that your model complies with the competition rules please visit the F1 in Schools website here 3 1 3 C02 Canister Settings Clicking on the C02 Canister Settings button from the left hand panel of the F1 VWT interface causes the following to appear The first parameter within this group use and display co2 canister is used to switch on or off the display and use of the CO2 bottle within the simulation If set to false the remaining parameters within this group will have no effect on the case However if the C02 Canister is being used within the case then the height of co2 canister parameter is used to set the height of the CO2 bottle within the display NOTE The height of the C02 canister is bound by the competition technical regulations The F1 VWT attempts to inform the user of any rule contraventions but to ensure that your model complies with the competition rules please visit the F1 in Schools website here 3 2 Boundary Conditions Clicking on the Wind Speed button from the left hand panel of the interface accesses the boundary condition settings for the case as seen below As can be seen from above there exists the single tunnel wind speed parameter as the sole boundary condition for the case By default the wind speed is set to 18 m s Should a user wish to alter this they can simply type the desired value within the white box to reset

    Original URL path: http://www.cham.co.uk/phoenics/d_sapps/f1-vwt/docs/f1_class/f1.htm (2016-02-15)
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  • descr-en
    4 The rotation angle mode The second rotation mode corresponds more closely to what is understood as rotation in normal speech It will be illustrated by first giving object 1 its rectangular shape again by choosing cube 14 again from the list of possible shapes for object 1 and then choosing rotang rather than rot24 as the rotation mode The menu items then offered include rotation centre wsl etc and rotation angle about x y or z axis Let us choose so as to see what happens wsl as rotation centre and rotation about y axis 30 degrees Click then on the display scenario button Something similar to the following image should be revealed Evidently the block has been tilted 30 degrees to the right as a consequence of the entries into the menu 2 2 c 4 Influence on the computed flow Activation of the flow simulating calculation by clicking the Run button in due course reveals that PHOENICS has taken note of the changes made and has produced a corresondingly different but still two dimensional flow pattern If it is desired to produce by rotation a three dimensional flow pattern a further rotation about say the z axis can procure this Let this then be also 30 degrees Then the consequent rotation and flow pattern alterations are as illustrated in the following images 2 3 2D walls and plates The three objects which are now to be considered have the names wall w wall e and in plate and they are numbered respectively 4 3 and 5 They are grouped together because each exhibits in the Q1 file the defining line OBJ TYPE PLATE Their effects on the flow differ in that in plate has a flow through it inhibiting effect as well as exerting friction on both of its sides Wall w and wall e do not have to exert this effect because they are situated at domain boundaries The distinction is made plain by what is printed in the RESULT file as a record of the instructions which it has received as may be seen in the following extract Parent VR object for this patch is ONAM3 PATCH OB4 EWALL 20 20 1 10 9 15 1 1 COVAL OB4 V1 1 0 COVAL OB4 W1 1 0 Parent VR object for this patch is ONAM4 PATCH OB5 WWALL 1 1 1 10 1 8 1 1 COVAL OB5 V1 1 0 COVAL OB5 W1 1 0 Parent VR object for this patch is ONAM5 PATCH OB6 L EWALL 5 5 1 10 6 14 1 1 COVAL OB6 L U1 FIXVAL 0 COVAL OB6 L V1 1 0 COVAL OB6 L W1 1 0 Parent VR object for this patch is ONAM5 PATCH OB6 H WWALL 6 6 1 10 6 14 1 1 COVAL OB6 H V1 1 0 COVAL OB6 H W1 1 0 Only ONAM5 viz in plate has two patches of EWALL and WWALL types respectively and it alone has a set U1 to zero line namely COVAL OB6 L U1 FIXVAL 0 The above settings are made by Satellite automatically That is one of the advantages of the virtual reality style of object description Settings via the menu The parameters of the thin plate objects which can be set via menus in this Tutorial are shown in the following image The objects appear in the order wall w wall e and in plate For each the x size is 0 0 confirming their 2D nature Each is given the shape cube11 but this means no more that that they are rectangular planes Even more meaningless is the ascribed rotation index 1 for any other of the 24 possibilities would effect no change Rotations of the rotang mode are not permitted for 2D grid aligned objects If however the shape is changed from cube to wedge the rotation index does exert an influence as is shown by the next two images in which in plate is given the values 5 and 13 respectively In order to introduce this change simply type the word wedge in the object 5 geometry box to get what follows Of the three it is in plate which has the greatest influence on the flow as may be seen by performing runs with f rather than t in the top boxes of each object in turn for it is in plate which causes the incoming flow to be deflected before flowing over in block Removal of wall w and wall e by contrast would remove only their modest frictional effects which incidentally in plate also exerts 2 4 2D apertures 2 4 a Changing the VR shape What has been stated about thin plates is true with obvious differences about apertures also The corresponding menu is shown below The following image shows one picture of the flow which ensues when object 7 the inlet is given the shape wedge and the rotation index remains at 1 This can be done as we already know by typing the word wedge instead of cube3t in the shape of object 7 box The grid is the rather coarse default and contours are of x direction velocity Evidently the flow is entering only through the lower left hand half of the original inlet aperture In principle any existing shape of inlet can be constructed in this way one needs only to be able to call in the dat file which defines its facets and to work out which is the appropriate rotation index Since those conditions especially the second are not always easy to meet it will now be explained that there are other means of obtaining the same end and that sometimes they are more convenient Answering as patch to the inlet treatment question of the General menu opens the door 2 4 b The use of patches as alternatives 2 4 b 1 Patches with indices as arguments In the early years of PHOENICS indeed until the arrival of VR solid objects were represented by way of collections of cells containing some other material than the domain fluid and their locations were defined by statements in the Q1 of the form PATCH patch name INIVAL ixf ixl iyf iyl izf izl itf itl wherein ixf ixl iyf ixl etc were the first and last indices of the cells occupied in the x y etc directions Such PATCH statements appear to this day as has been seen above Users know where their objects are but not necessarily where the cells are However a post VR dot patch innovation allows them to put a dot in front of the patch name and then to employ real rxf rxl etc rather than indicial arguments thus PATCH patch name INIVAL rxf rxl ryf ryl rzf rzl rtf rtl or for a mass and momentum source ptach such as an inlet PATCH patch name WEST rxf rxl ryf ryl rzf rzl rtf rtl Now a final post VR innovation must be described the COVAL function of In Form Clicking on the hyperlinks will lead to full explanations of these terms but here it sufffices to show two examples of their use and then to explain how they were created 2 4 b 2 In plate object 5 as a dot patch In section 2 3 it was shown how the shape of the in plate object could be changed by invoking a wedge rather than a cube as the shape Here another means of doing so will be illustrated Specifically the shape of the lower edge will be made sinusoidal How this is done is revealed by the following lines from the underlying PQ1 else the dot patch alternative rxf posx5 xulast 1000 rxl posx5 xulast 1000 ryf posy5 yvlast 1000 ryl posy5 sizy5 yvlast 1000 rzf posz5 zwlast 1000 rzl posz5 sizz5 zwlast 1000 PATCH onam5 EAST rxf rxl ryf ryl rzf rzl 1 1 condtn zg gt posz5 1 sin 3 1416 yg sizy5 source of u1 at onam5 is coval 1 e10 0 0 if condtn endif wherein the first few lines dictate the bounding box of the plate that beginning source sets the x direction velocity to zero when condtn is true and the line above it which contains the sine function dictates where the setting is to be made That these lines are effective is shown by the following image which displays contours of x direction velocity just downstream of in plate with values of NY and NZ increased from their defaults in order to intensify the effect Their sinusoidal shape is very clear The condtn formula can of course be varied without limit therefore any desired shape of plate can be easily created Two comments are needed about the above shown PQ1 lines for example ryf posy5 yvlast 1000 ryl posy5 sizy5 yvlast 1000 namely the division by yvlast indicates that ryf is a non dimensional co ordinate and the multiplication by 1000 is a not worth explaining trick concerned with the inner workings of the Satellite coding 2 4 b 3 Circular inlets and outlets A similar technique can be employed for altering the shapes of inlets and outlets Thus the following diagrams illustrate on the left and right respectively an inlet in which an inner circular section is blocked and an outlet in which the circular section is open The grid is uniform with 40 and 60 intervals in the y and z directions respectively The contour plots are of x direction velocity and the chosen planes are close to but not precisely at the planes of the apertures The PHOENICS run which produces the just shown results was launched by way of menus already shown but underlying these were some passages in the parameterised Q1 file which will now be discussed For the inlet they are else the dot patch alternative rxf posx7 zwlast 1000 rxl posx7 sizx7 xulast 1000 ryf posy7 zwlast 1000 ryl posy7 sizy7 yvlast 1000 rzf posz7 zwlast 1000 rzl posz7 sizz7 zwlast 1000 patch onam7 west rxf rxl ryf ryl rzf rzl 1 1 which desctibe the bounding box of the patch real ycn zcn char radsq ycn posy7 0 5 sizy7 zcn posz7 0 5 sizz7 radsq yg ycn 2 zg zcn 2 condtn radsq gt 0 04 stored var rgt is 1 if radsq gt 0 04 which define the centre of the circle and its radius squared also define the outside circle condition and source of p1 at onam7 is invelx with fixf if condtn coval onam7 u1 onlyms invelx coval onam7 tem1 onlyms intem endif which applies the sources of mass momentum and thermal energy For the outlet the statements are identical except that 8 replaces 7 because that is the object number and lt replaces gt because the active area is now inside rather than outside the circle 2 4 c Reminder of for whom this tutorial is intended Some readers having persisted to this point may be thinking That s all very clever and perhaps useful but can an ordinary PHOENICS user be expected to learn all that A pertinent question to which the answer is Certainly not It is the prospective PQ1 writer who should learn it and who should if it is relevant to the SimScene which is to be created enable the ordinary user to exploit the available facilities How is this to be done Simply by utilising the existing facilities connecting PQ1 scene xml and what appears in the user s screen Does the user interested in circular inlets wish to choose the centre and radius of the circle The PQ1 writer should find it is easy xcen ycen zcen and radsq already having been defined as parameters if this tutorial has been successful to know what to do Readers might wish to ask themselves how they would make this possible before activating and exploring the provisos for radius adjustment already made in this tutorial in the menus for the inlet and outlet objects 2 5 Variables solved This menu group allows the setting of solved for variables as the following picture shows These are pressure p1 and temperature tem1 as well as the three Cartesian directon velociy components u1 v1 and w1 They can be set either to t meaning true or f false The index 1 indicates that this is a case when only one fluid is used no provision having been made in this tutorial for activating the two intermingling fluids capabilities of PHOENICS That individual variables can be set t or f does not imply that any arbitrary collection of settings is reasonable Thus presssure should always be solved for otherwise mass continuity will not be preserved Solvng for temperature might be switched off if thermal effects were of no interest but solving for it alone although possible would be unwise unless physically plausible velocity distributions had been imposed That is all that will be said about the topic here 2 6 Material properties 2 6 a Properties of solid objects A common practice is to select the properties of a material by assigning it an index indicating where in a so called PROPS file its properties are defined The PHOENICS solver module consults this file and so can its users if they wish The selection of the material of the solid objects can be selected via the top three boxes of the menu shown below When the drop down menu of the object 1 box is activated what is seen is shown below This enables other materials to be selected with their correspondngly different densities thermal conductivities etc all being regarded as independent of temperature 2 6 b Properties of the fluid The properties of the fluid can be selected in two ways namely by specifying the values of particular properties such as viscosity as independent of temperature constants or by selecting them by name The image below shows the names of the fluids which are on offer If one of these is selected the information which is drawn from the PHOENICS library of materials includes how the properties vary with temperature 2 7 Models A page with this title is provided in most SimScenes in order to alllow the switching on and off of physico chemical models for processes such as turbulence radiation combustion etc Labyrinth is not rich in this respect as shown here It allows turbulence to be represented either not at all or else by the simplest of all lvel model As is clear from the above image none of the models is used at present 2 8 Boundary conditions The boundary coditions which can be set here are fluid inlet velocity i e in X direction fluid inlet temperature temperature of high block h block and heat flux to l block 2 9 Computational grid The computational grid page contains grid settings i e the number of grid cells in X Y and Z directions and also the number of iterations Increasing the number of iterations it is possible to improve the convergence of the calculation process Note that in this page 3 dimensionality is introduced by making the number of cells in Y direction equal to 10 rather than to 1 used in the two dimensonal simulations in the older labyrinth tutorials mentioned above 2 10 Graphical Output In the graphical output page a user sets his control on the display of streamlines upon termination of the calculation Here a principal possibility is made evident when in the first box either t true or f false is chosen In case a user chooses to display streamlines their number is entered in the second box How and where this possibility is realized will be shown in section 4 3 Some further Labyrinth results Some results of flow simulations have been presented above particularly in order to illustrate the effects on the flow of changing object orientations Some further results will now be presented in order to illustrate other consequences of changed data settings Click on the Run button to start the calculation and upon its termination click on the Display results graphically button to open the VR Viewer We will here present some results of the simulation made 3 1 Pressure contours Pressure contours on Y plane look like what follows if you click on the Slice Direction Y button and on the Contour toggle button from the tool bar 3 2 Velocity contours To present velocity contours on the same plane click on Select velocity button V and you get what follows You might wish to display velocity contours on X planes then you will see the following picture Here for better visibility we selected the wireframe display mode by clicking on the Wireframe toggle button and similar representation of velocity contours on the Z plane will look as follows 3 3 Temperature contours It is now time to look at temperatures The following picture is obtained when temperature has been chosen as a variable in question the box T contours on Y plane i e along the labyrinth and the Wireframe mode being switched off by another click on the Wireframe toggle button It might be interesting to observe temperature contours inside the cone which can be done by first clicking on this object to select it then right clicking on the selected object opens the context menu in a usual manner Select the Hide object s command and the following picture appears The material chosen by default for the cone was a highly conducting copper with the constant properties appropriate to 27 degrees Celsius Besides the heat flux introduced from the bottom lower plate was uniform and 100 W only This is the explanation why we got so uniform temperature distribution inside the cone Let us now increase the heat flux from the bottom lower plate and choose steel as the cone material But first of all we should reveal our cone object on the scene by

    Original URL path: http://www.cham.co.uk/phoenics/d_sapps/labyrinth/docs/descr_en.htm (2016-02-15)
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  • Heat Isle Special Application Package
    as shown below The scene contains Some buildings dark grey Some roads brown A grass area green A section of river blue and The surrounding ground light grey The blue arrow points North and the red arrow indicates the wind direction in this example from the East The scene is illuminated by the sun The big orange ball shows the sun location at the time of the simulation The small orange balls show the position of the sun at each hour during daytime and the small grey balls show the position of the sun during the night 8 12 Parameters which users may alter via menus Location The domain size in X Y and Z directions The default sizes are 1250m 625m 200m The origin of the scene within the domain Geometrical The name of the buildings file Whether to include the road or not Whether to include the river or not Whether to include the grass or not Whether to include clipping planes which can help to visualise the scene later or not Physical properties Whether to include buoyancy or not The thermal conductivities of the buildings road river and ground The grass area if included has the same conductivity as the ground Emissivities of the buildings road grass river and ground The properties of the elements are not well known In steady state the only important properties are the thermal conductivity and emissivity The conductivity of the ground will depend on the composition and water content The buildings are represented very simplistically as a single body In reality they comprise a mixture of materials and internal air space The conductivity of the buildings should reflect this mixture of materials The emissivity will control how well the surface of the element can radiate away the heat from the sun The best values for these properties can be estimated by comparing solutions to known results and adjusting the properties until acceptable agreement of trends at least is achieved Boundary conditions The direction the wind is blowing from By default from the East The orientation of the domain relative to North By default the Y axis points North The wind speed at the reference height of 10m above the ground by default 2 0m s The ambient air temperature by default 32 deg C The latitude at which the scene is located by default 51deg The date on which the simulation is taking place by default 1st June The time of day of the simulation by default midday 12 00hrs The direct solar radiation by default 500 W m 2 This represents the radiation which has passed directly through the atmosphere from the sun at the particular latitude date and time of day The diffuse solar radiation by default 100 W m 2 This represents the radiation scattered by the atmosphere back to the earth at the particular latitude date and time of day The temperature of the sky This controls how much heat radiates back to the sky it is

    Original URL path: http://www.cham.co.uk/phoenics/d_sapps/heatisle/docs/descr_en.htm (2016-02-15)
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  • Solvers
    solver with block correction but without print out Conjugate Residual Solver KIVA II with several pre conditioners MADI which is modification of well known ADI solver PHOENICS s solver PHSOL which is the same as default but with detailed print out Conjugate Gradient SK CG is standard conjugate gradient solver with some pre conditioners from SPARSEKIT Conjugate Gradient Method Normal Residual equation CGNR with some pre conditioners from SPARSEKIT Bi Conjugate Gradient Method BCG with some pre conditioners from SPARSEKIT Bi Conjugate Gradient Method with partial pivoting DBCG with some pre conditioners from SPARSEKIT Bi Conjugate Gradient Method stabilized BCGSTAB with some pre conditioners from SPARSEKIT Transpose Free Quasi Minimum Residual method TFQMR with some pre conditioners from SPARSEKIT Full Orthogonalization Method FOM with some pre conditioners from SPARSEKIT Generalized Minimum RESidual method GMRES with some pre conditioners from SPARSEKIT Flexible version of Generalized Minimum RESidual method FGMRES with some pre conditioners from SPARSEKIT Direct versions of Quasi Generalize Minimum Residual method DQGMRES with some pre conditioners from SPARSEKIT Preconditioned GMRES solver PGMRES with ILUT pre conditioner from SPARSEKIT Conjugate Residual solver CNGR with Jacobi or ILU pre conditioners Modified Strongly Implicit Procedure MSIP The most of solvers can utilise pre conditioners Solvers from package SPARSEKIT can use following pre conditioners each Incomplete LU factorization with dual truncation strategy ILUT ILU with single dropping diagonal compensation MILUT ILUD level k ILU ILUK simple ILU 0 preconditioning ILU 0 which is recommended by author for testing purposes only MILU 0 preconditioning MILU 0 which is recommended by author for testing purposes only Conjugate Residual Solver KIVA II can be used with all pre conditioners from SPARSEKIT with solvers PHSOL and MADI as pre conditioners and with point by point and Jackobi solvers as pre conditioners The main purpose of creation SimScene

    Original URL path: http://www.cham.co.uk/phoenics/d_sapps/solvers/docs/descr_en.htm (2016-02-15)
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  • descr
    m s and delivered solids volume fraction To adjust these values the SimScene user need simply to enter the desired value in the white box adjacent to the parameter they wish to change 2 4 Output Settings Clicking on the Output settings button from the left hand panel of the interface accesses the parameters governing the output for the scenario as seen within the image below The parameters seen above determine what will be printed to the inforout file at the end of the simulation The first parameter print input settings simply prints the input data for the case when set to true The print deposition velocity and suspended flow indicator when set to true tells EARTH to calculate the particle deposition velocity based on the user set data and then compare this value with the user set slurry superficial velocity If the inflow velocity exceeds the deposition velocity the case is deemed to be in the fully susended flow regime In such a case the suspended flow indicator is 1 0 if the case is not in the fully suspended flow regime the suspended flow indicator takes the value 0 0 Both the deposition velocity and the suspended flow indiator are then printed to the inforout file as DEP VELOCITY and FULLY SUSPENDED respectively The final parameter within the Output settings group print pipe pressure gradient will print the calculated pressure gradient along the lenght of the pipe to the inforout file at the end of the simulation run 2 5 Computational Grid Clicking on the Computational Grid button from the left hand panel of the slurry SimScene interface will cause the following to be displayed This parameter group contains two parameters relating to the computational grid for the case namely no of cells in circumferential direction x direction and no of cells in axial direction z direction By adjusting these values the grid cell distribution throughout the domain will be altered for the subsequent run The grid distribution in the radial direction is not available to be user set since the numerics of the case are dependent upon a strict criterion bounding the dimensionless wall distance to the first grid point As a result the case is set up to auto grid in the radial y direction to ensure that this criterion is satisied for all choices of pipe diameter 2 6 Numerical Clicking on the Numerical button from the left hand panel of the interface causes the following to appear The Numerical parameter group contains some settings for the PHOENICS solver EARTH It is from within this parameter group that the SimScene user can set the number of iterations sweeps to be performed by EARTH during the calculation In addition the user can also set the error cut off criteria which is the convergence criteria the solver will adopt for the calculation When the sums of the errors for each solved for variable within the simulation drop below the error cut off criteria value the solver will

    Original URL path: http://www.cham.co.uk/phoenics/d_sapps/slurry/docs/descr_en.htm (2016-02-15)
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  • Information regarding the HEVACOMP CFD MODULE
    CHAM s PHOENICS FLAIR CFD solver The room geometry information including the surface temperatures and convection coefficients together with room objects like diffusers and heat sources is created parametrically in Hevacomp s new Simulation module The complete input file is then passed to the CFD solver provided by CHAM A key issue is the accurate modelling of diffusers and grilles CHAM in co operation with Hevacomp has implemented diffuser objects based on ASHRAE research The new Hevacomp Simulation package enables detailed heat gain simulations with detailed shadow analysis heat loss simulations summertime temperatures including mixed mode ventilation studies overheating frequencies and extensive energy consumption and carbon calculations studies Prices start from 531 per year For further information see Hevacomp Dynamic Simulation Features Hevacomp incorporates a number of air distribution devices with manufacturers data It has an equipment library for localising heat gains as well as a furniture library When a CFD module project file is written by Hevacomp all the boundary conditions are automatically set up as a result of the Design Simulation i e convection coefficients and surface temperature as well as the room surfaces geometry The user does not have to set these manually The simulation engine for both PHOENICS FLAIR and Hevacomp s CFD module is the same The pressure velocity and temperature variables are solved and reported in the same manner Restrictions Whilst the Hevacomp CFD module is a very fast and efficient process for producing the CFD input file the shape and complexity of the room model is defined both the options solely available within Hevacomp s CAD environment as the PHOENICS FLAIR VR Editor pre processor is disabled in this version Similarly Hevacomp s CFD simulations solutions are currently limited to a single room With PHOENICS FLAIR any shape with any complexity can be

    Original URL path: http://www.cham.co.uk/hevacomp/info.php (2016-02-15)
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  • Questions and Answers: HEVACOMP CFD MODULE
    support Hevacomp CFD module Information Questions Answers Download PHOENICS News Winter 2015 Flash Version of Latest News Letter Questions and Answers HEVACOMP CFD MODULE HEVACOMP CFD Page under construction Copyright

    Original URL path: http://www.cham.co.uk/hevacomp/questions.php (2016-02-15)
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