how to impose experimental data as boundary condition in Fluent 6.3.26?

Important detail: i don´t wanna use any equation, using a software as Origin Pro to extract a formula for the heating and after, for the decay of heat flux!

Thanks for helping me!

The data are:

t [s] q" [W m^-2]

0 0.00000000000000000 0.222 0.00000000000000000 0.444 0.00000000000000000 0.666 0.00000000000000000 0.888 0.00000000000000000 1.11 0.00000000000000000 1.332 0.00000000000000000 1.554 0.00000000000000000 1.776 0.00000000000000000 1.998 0.00000000000000000 2.22 0.00000000000000000 2.442 0.00000000000000000 2.664 0.00000000000000000 2.886 376082.30425690200000000 3.108 2039587.70396777000000000 3.33 3407336.78002498000000000 3.552 4631631.80395514000000000 3.774 5320092.39034934000000000 3.996 5107853.68496400000000000 4.218 5582111.96002751000000000 4.44 6392412.51161420000000000 4.662 7193214.58434504000000000 4.884 7914424.96035032000000000 5.106 8552122.49996491000000000 5.328 9107928.48741737000000000 5.55 9594306.16570057000000000 5.772 10022056.50605620000000000 5.994 10400022.18697810000000000 6.216 10729516.32724670000000000 6.438 11025924.42841300000000000 6.66 11290567.19953960000000000 6.882 11523437.05034460000000000 7.104 11728473.33716960000000000 7.326 11920727.58915910000000000 7.548 12094317.33778720000000000 7.77 12249895.34730310000000000 7.992 12394004.44076410000000000 8.214 12526325.82632740000000000 8.436 12646199.14946170000000000 8.658 12756577.02985310000000000 8.88 12858764.99599990000000000 9.102 12954076.16668300000000000 9.324 13042176.56949570000000000 9.546 13122094.64834590000000000 9.768 13196767.84235570000000000 9.99 13267190.47846290000000000 10.212 13333347.37610350000000000 10.434 13393940.59706100000000000 10.656 13450275.66983400000000000 10.878 13505624.00595100000000000 11.1 13555082.28326010000000000 11.322 13601261.55875870000000000 11.544 13646135.30575870000000000 11.766 13687730.05094810000000000 11.988 13724413.88370360000000000 12.21 13763389.98161380000000000 12.432 13798760.69558870000000000 12.654 13833152.26318970000000000 12.876 13861646.18170080000000000 13.098 13892766.33777320000000000 13.32 13922892.16690760000000000 13.542 13948441.05601480000000000 13.764 13976608.59240130000000000 13.986 13997899.33332400000000000 14.208 14019516.45637130000000000 14.43 14041786.34366800000000000 14.652 14064382.61308930000000000 14.874 14083715.06126400000000000 15.096 14102705.94675010000000000 15.318 14121378.04039350000000000 15.54 14138737.01525640000000000 15.762 14157075.13649310000000000 15.984 14174107.72923130000000000 16.206 14188848.05681480000000000 16.428 14202601.64774240000000000 16.65 14217341.97532600000000000 16.872 14229463.65563030000000000 17.094 14241251.36352790000000000 17.316 14253039.07142560000000000 17.538 14265487.13385450000000000 17.76 14274990.16687950000000000 17.982 14285464.75599660000000000 18.204 14293001.90599170000000000 18.426 14305115.99601400000000000 18.648 14314945.41116370000000000 18.87 14324114.47178210000000000 19.092 14332957.15027580000000000 19.314 14340820.68239550000000000 19.536 14349663.36088930000000000 19.758 14355553.41969710000000000 19.98 14364403.68847280000000000 20.202 14368327.86425070000000000 20.424 14376191.39637050000000000 20.646 14385034.07486420000000000 20.868 14388965.84092410000000000 21.09 14397155.75516850000000000 21.312 14404032.55063230000000000 21.534 14411235.72822070000000000 21.756 14417459.75943520000000000 21.978 14424336.55489900000000000 22.2 14430886.96823820000000000 22.422 14437763.76370190000000000 22.644 14441695.52976180000000000 22.866 14447919.56097630000000000 23.088 14452504.09128550000000000 23.31 14458728.12250000000000000 23.532 14464625.77158980000000000 23.754 14469536.68402360000000000 23.976 14475760.71523810000000000 24.198 14481658.36432790000000000 24.42 14486569.27676180000000000 24.642 14495085.57313090000000000 24.864 14502615.13284400000000000 25.086 14504907.39799860000000000 25.308 14510152.28283910000000000 25.53 14516702.69617820000000000 25.752 14522592.75498600000000000 25.974 14528164.02195120000000000 26.196 14534061.67104100000000000 26.418 14540278.11197350000000000 26.64 14547488.87984390000000000 26.862 14552073.41015310000000000 27.084 14557637.08683630000000000 27.306 14566160.97348730000000000 27.528 14569758.76714060000000000 27.75 14575330.03410570000000000 27.972 14581554.06532020000000000 28.194 14587778.09653470000000000 28.416 14598252.68565170000000000 28.638 14600544.95080630000000000 28.86 14604803.09899090000000000 29.082 14608734.86505070000000000 29.304 14615938.04263920000000000 29.526 14619543.42657440000000000 29.748 14625441.07566420000000000 29.97 14630025.60597340000000000 30.192 14635915.66478130000000000 30.414 14640834.16749710000000000 30.636 14644765.93355700000000000 30.858 14650003.22811550000000000 31.08 14654587.75842470000000000 31.302 14656227.25933000000000000 31.524 14661138.17176380000000000 31.746 14660811.78963920000000000 31.968 14667362.20297830000000000 32.19 14670967.58691350000000000 32.412 14675878.49934740000000000 32.634 14677844.38237730000000000 32.856 14679149.91087590000000000 33.078 14682428.91268650000000000 33.3 14685373.94209040000000000 33.522 14689632.09027500000000000 33.744 14690292.44480620000000000 33.966 14696182.50361410000000000 34.188 14698474.76876870000000000 34.41 14703059.29907790000000000 34.632 14707643.82938710000000000 34.854 14709609.71241700000000000 35.076 14711249.21332230000000000 35.298 14716494.09816280000000000 35.52 14717473.24453680000000000 35.742 14721078.62847200000000000 35.964 14727302.65968650000000000 36.186 14731887.18999570000000000 36.408 14734832.21939960000000000 36.63 14737450.86667880000000000 36.852 14739416.74970880000000000 37.074 14744988.01667390000000000 37.296 14748919.78273380000000000 37.518 14752843.95851170000000000 37.74 14754483.45941700000000000 37.962 14758088.84335220000000000 38.184 14763652.52003540000000000 38.406 14768897.40487590000000000 38.628 14772168.81640440000000000 38.85 14773808.31730970000000000 39.072 14778392.84761890000000000 39.294 14781337.87702280000000000 39.516 14786582.76186330000000000 39.738 14791167.29217250000000000 39.96 14795751.82248170000000000 40.182 14802302.23582090000000000 40.404 14808852.64916000000000000 40.626 14813110.79734450000000000 40.848 14819661.21068370000000000 41.07 14827524.74280340000000000 41.292 14835380.68464120000000000 41.514 14842257.48010500000000000 41.736 14851760.51313000000000000 41.958 14857324.18981320000000000 42.18 14860276.80949910000000000 42.402 14865514.10405760000000000 42.624 14873704.01830200000000000 42.846 14878948.90314250000000000 43.068 14882546.69679570000000000 43.29 14889757.46466620000000000 43.512 14890410.22891550000000000 43.734 14896634.26013000000000000 43.956 14901871.55468850000000000 44.178 14904490.20196770000000000 44.4 14909727.49652630000000000 44.622 14914319.61711740000000000 44.844 14916611.88227200000000000 45.066 14918251.38317730000000000 45.288 14921849.17683060000000000 45.51 14928725.97229430000000000 45.732 14929386.32682560000000000 45.954 14932984.12047890000000000 46.176 14936915.88653880000000000 46.398 14936915.88653880000000000 46.62 14938555.38744400000000000 46.842 14936263.12228940000000000 47.064 14941174.03472330000000000 47.286 14942487.15350390000000000 47.508 14943792.68200260000000000 47.73 14946745.30168840000000000 47.952 14949690.33109240000000000 48.174 14948377.21231180000000000 48.396 14948377.21231180000000000 48.618 14947071.68381310000000000 48.84 14945105.80078320000000000 49.062 14945758.56503250000000000 49.284 14947724.44806240000000000 49.506 14948050.83018710000000000 49.728 14949029.97656110000000000 49.95 14951329.83199760000000000 50.172 14951656.21412230000000000 50.394 14948050.83018710000000000 50.616 14948050.83018710000000000 50.838 14952635.36049630000000000 51.06 14951003.44987300000000000 51.282 14949029.97656110000000000 51.504 14946745.30168840000000000 51.726 14947398.06593780000000000 51.948 14944453.03653380000000000 52.17 14944119.06412720000000000 52.392 14940194.88834930000000000 52.614 14942813.53562860000000000 52.836 14943466.29987790000000000 53.058 14942487.15350390000000000 53.28 14941826.79897260000000000 53.502 14940521.27047400000000000 53.724 14938881.76956870000000000 53.946 14935936.74016480000000000 54.168 14934297.23925950000000000 54.39 14933310.50260350000000000 54.612 14932004.97410490000000000 54.834 14933644.47501020000000000 55.056 14932657.73835420000000000 55.278 14929712.70895030000000000 55.5 14927086.47138910000000000 55.722 14925780.94289040000000000 55.944 14922835.91348650000000000 56.166 14924467.82410980000000000 56.388 14921849.17683060000000000 56.61 14917264.64652140000000000 56.832 14918904.14742660000000000 57.054 14917591.02864600000000000 57.276 14917264.64652140000000000 57.498 14915625.14561610000000000 57.72 14916285.50014740000000000 57.942 14915951.52774070000000000 58.164 14913332.88046150000000000 58.386 14911040.61530690000000000 58.608 14911040.61530690000000000 58.83 14911700.96983820000000000 59.052 14910714.23318220000000000 59.274 14909401.11440160000000000 59.496 14907108.84924700000000000 59.718 14903511.05559380000000000 59.94 14904163.81984310000000000 60.162 14903511.05559380000000000 60.384 14901545.17256380000000000 60.606 14898918.93500260000000000 60.828 14896300.28772330000000000 61.05 14897287.02437930000000000 61.272 14895973.90559870000000000 61.494 14895973.90559870000000000 61.716 14894008.02256870000000000 61.938 14891062.99316480000000000 62.16 14890410.22891550000000000 62.382 14887457.60922960000000000 62.604 14883859.81557640000000000 62.826 14884186.19770100000000000 63.048 14884186.19770100000000000 63.27 14885165.34407500000000000 63.492 14722057.77484600000000000 63.714 13725727.00248420000000000 63.936 12509293.23358920000000000 64.158 11340678.24109810000000000 64.38 10285720.13080890000000000 64.602 9343424.57578352000000000 64.824 8511833.28327415000000000 65.046 7778832.16325843000000000 65.268 7130000.43902371000000000 65.49 6552898.39745119000000000 65.712 6053095.02842145000000000 65.934 5595212.02767758000000000 66.156 5182857.81526758000000000 66.378 4810133.22404525000000000 66.6 4476381.69462028000000000 66.822 4173748.80321127000000000 67.044 3898626.12977024000000000 67.266 3647415.12161574000000000 67.488 3415526.69426939000000000 67.71 3203943.03021797000000000 67.932 3016599.69066233000000000 68.154 2838751.79384974000000000 68.376 2671713.97661722000000000 68.598 2521379.33388539000000000 68.82 2378578.04600766000000000 69.042 2250514.80862889000000000 69.264 2126382.57828180000000000 69.486 2013058.15043018000000000 69.708 1907267.83646086000000000 69.93 1805407.01146683000000000 70.152 1710424.49999298000000000 70.374 1621664.50167722000000000 70.596 1539782.81688164000000000 70.818 1464124.40427234000000000 71.04 1391086.15699869000000000 71.262 1323288.24039636000000000 71.484 1257783.34797681000000000 71.706 1197518.02720038000000000 71.928 1138235.64793892000000000 72.15 1081901.33419416000000000 72.372 1028842.22711898000000000 72.594 979058.32671335800000000 72.816 930256.60879451000000000 73.038 886695.22154696900000000 73.26 842152.41084085400000000 73.482 801866.23026288100000000 73.704 762562.99119987700000000 73.926 725552.77631966800000000 74.148 688869.70259231700000000 74.37 658082.45628710600000000 74.592 627949.87180171000000000 74.814 596507.35645412600000000 75.036 565719.80653763600000000 75.258 538535.36347176800000000 75.48 511678.06155875900000000 75.702 482528.34268551100000000 75.924 458946.32334488900000000 76.146 433726.85247512200000000 76.368 411127.39513537000000000 76.59 389838.17226908500000000 76.812 367566.46330474800000000 77.034 348242.59214866200000000 77.256 325970.57957304700000000 77.478 306974.22908391700000000 77.7 291252.78165307600000000 77.922 272911.39659504000000000 78.144 253259.92886917700000000 78.366 237866.07800811200000000 78.588 222472.37895268700000000 78.81 205768.59722943500000000 79.032 191684.98084183600000000 79.254 180221.52978989200000000 79.476 166137.91340229300000000 79.698 154019.42101643500000000 79.92 142555.96996449100000000 80.142 129454.99148058200000000 80.364 115698.81985712100000000 80.586 103252.88270712600000000 80.808 94737.19356061140000000 81.03 84583.90107931340000000 81.252 72465.37833232750000000 81.474 64277.22503333380000000 81.696 55761.55106738340000000 81.918 48228.45428286710000000 82.14 38730.19554520060000000 82.362 30214.51398896830000000 82.584 23336.45094808350000000 82.806 15803.35416356720000000 83.028 7287.67867956041000000 83.25 0.00000000000000000 83.472 0.00000000000000000 83.694 0.00000000000000000 83.916 0.00000000000000000 84.138 0.00000000000000000 84.36 0.00000000000000000 84.582 0.00000000000000000 84.804 0.00000000000000000 85.026 0.00000000000000000 85.248 0.00000000000000000 85.47 0.00000000000000000 85.692 0.00000000000000000 85.914 0.00000000000000000 86.136 0.00000000000000000 86.358 0.00000000000000000 86.58 0.00000000000000000 86.802 0.00000000000000000 87.024 0.00000000000000000 87.246 0.00000000000000000 87.468 0.00000000000000000 87.69 0.00000000000000000 87.912 0.00000000000000000 88.134 0.00000000000000000 88.356 0.00000000000000000 88.578 0.00000000000000000 88.8 0.00000000000000000 89.022 0.00000000000000000 89.244 0.00000000000000000 89.466 0.00000000000000000 89.688 0.00000000000000000 89.91 0.00000000000000000 90.132 0.00000000000000000 90.354 0.00000000000000000 90.576 0.00000000000000000 90.798 0.00000000000000000 91.02 0.00000000000000000 91.242 0.00000000000000000 91.464 0.00000000000000000 91.686 0.00000000000000000 91.908 0.00000000000000000 92.13 0.00000000000000000 92.352 0.00000000000000000 92.574 0.00000000000000000 92.796 0.00000000000000000 93.018 0.00000000000000000 93.24 0.00000000000000000 93.462 0.00000000000000000 93.684 0.00000000000000000 93.906 0.00000000000000000 94.128 0.00000000000000000 94.35 0.00000000000000000 94.572 0.00000000000000000 94.794 0.00000000000000000 95.016 0.00000000000000000 95.238 0.00000000000000000 95.46 0.00000000000000000 95.682 0.00000000000000000 95.904 0.00000000000000000 96.126 0.00000000000000000 96.348 0.00000000000000000 96.57 0.00000000000000000 96.792 0.00000000000000000 97.014 0.00000000000000000 97.236 0.00000000000000000 97.458 0.00000000000000000 97.68 0.00000000000000000 97.902 0.00000000000000000 98.124 0.00000000000000000 98.346 0.00000000000000000 98.568 0.00000000000000000 98.79 0.00000000000000000 99.012 0.00000000000000000 99.234 0.00000000000000000 99.456 0.00000000000000000 99.678 0.00000000000000000 99.9 0.00000000000000000 100.122 0.00000000000000000 100.344 0.00000000000000000 100.566 0.00000000000000000 100.788 0.00000000000000000 101.01 0.00000000000000000 101.232 0.00000000000000000 101.454 0.00000000000000000 101.676 0.00000000000000000 101.898 0.00000000000000000 102.12 0.00000000000000000 102.342 0.00000000000000000 102.564 0.00000000000000000 102.786 0.00000000000000000 103.008 0.00000000000000000 103.23 0.00000000000000000 103.452 0.00000000000000000 103.674 0.00000000000000000 103.896 0.00000000000000000 104.118 0.00000000000000000 104.34 0.00000000000000000 104.562 0.00000000000000000 104.784 0.00000000000000000 105.006 0.00000000000000000 105.228 0.00000000000000000 105.45 0.00000000000000000 105.672 0.00000000000000000 105.894 0.00000000000000000 106.116 0.00000000000000000 106.338 0.00000000000000000 106.56 0.00000000000000000 106.782 0.00000000000000000 107.004 0.00000000000000000 107.226 0.00000000000000000 107.448 0.00000000000000000 107.67 0.00000000000000000 107.892 0.00000000000000000 108.114 0.00000000000000000 108.336 0.00000000000000000 108.558 0.00000000000000000 108.78 0.00000000000000000 109.002 0.00000000000000000 109.224 0.00000000000000000 109.446 0.00000000000000000 109.668 0.00000000000000000 109.89 0.00000000000000000 110.112 0.00000000000000000 110.334 0.00000000000000000 110.556 0.00000000000000000 110.778 0.00000000000000000

You can use a UDF with a interpolation function in which your experimental data is included or read.

Any ideas to build this C file? (name.C)

Like that?

/************************************************** ************/ /* */ /* User-Defined Function for Unsteady Flow in a Channel */ /* */ /* Fluent 6 */ /* */ /* Author: Frank Kelecy */ /* Date: January 2001 */ /* */ /* This function prescribes an oscillating static pressure */ /* at the channel exit. */ /* */ /************************************************** ************/

#include "udf.h"

DEFINE_PROFILE(unsteady_pressure, thread, position) {

float t, pressure; face_t f;

t = RP_Get_Real("flow-time");

pressure = (0.12*sin(2200*t)+0.737)*101325.0;

begin_f_loop(f, thread) {

F_PROFILE(f, thread, position) = pressure; } end_f_loop(f, thread)

}

4.3.7 DEFINE HEAT FLUX Description In spite of its name, the DEFINE HEAT FLUX macro is not to be used to explicitly set the heat ux along a wall. FLUENT computes the heat ux along a wall based on currently selected models to account for the diusive and radiative energy uxes (if any). You must only use a DEFINE HEAT FLUX UDF when you want to employ some other heat transfer mechanism that is not currently being modeled. The total heat ux at the wall will be the sum of the currently computed heat ux (based on the activated models) and the heat ux de ned by the UDF. Usage Macro: DEFINE HEAT FLUX (name, f, t, c0, t0, cid, cir) Argument types: face t f Thread *t cell t c0 Thread *t0 real cid[] real cir[] Function returns: void There are seven arguments to DEFINE HEAT FLUX: name, f, t, c0, t0, cid, and cir. You will supply name, the name of the UDF. f, t, c0, t0, cir[], and cid[] are variables that are passed by the FLUENT solver to your UDF. The passed variable, f, is an index that identi es a wall face within the given thread. t is a pointer to the thread on which the heat ux function is to be applied. c0 is an index that identi es the cell next to the wall, and t0 is a pointer to the adjacent cell's thread. cid[] and cir[] are real arrays that need to be computed by your UDF. Array cid[] stores the uid-side diusive heat transfer coecients, while array cir[] stores radiative heat transfer coecients. With these inputs provided to the function, the diusive heat

ux (qid) and radiative heat ux (qir) are computed by FLUENT according to the following equations: qid = cid[0] + cid[1]*C_T(c0,t0) - cid[2]*F_T(f,t) - cid[3]*pow(F_T(f,t),4) qir = cir[0] + cir[1]*C_T(c0,t0) - cir[2]*F_T(f,t) - cir[3]*pow(F_T(f,t),4) The sum of qid and qir de nes the total heat ux from the uid to the wall (this direction being positive ux), and, from an energy balance at the wall, equals the heat 4-32 c Fluent Inc. January 22, 2003 4.3 Model-Speci c DEFINE Macros

ux of the surroundings (exterior to the domain). Note that heat ux UDFs (de ned using DEFINE HEAT FLUX) are called by FLUENT from within a loop over wall faces. In order for the solver to compute C T and F T, the values you supply to cid[1] and ! cid[2] should never be zero. Example Section 11.5.2 provides an example of the P-1 radiation model implementation through a user-de ned scalar. An example of the usage of the DEFINE HEAT FLUX macro is included in that implementation. Hooking a Heat Flux UDF to FLUENT After the UDF that you have de ned using DEFINE HEAT FLUX is interpreted or compiled (see Chapter 7 for details), the name that you speci ed in the DEFINE macro argument will become visible in the User-De ned Function Hooks panel in FLUENT. See Section 8.2.7 for details on how to hook your DEFINE HEAT FLUX UDF to FLUENT.

Is anything like on page 4-23 of the file described below?

File FL61UDF.PDF (2532 KB)!

http://rapidshare.de/files/40976522/FL61UDF.PDF.html

Like the other link you gave me, it cannot download the file. But never mind, I give you my one simple of unsteady inlet velocity.

DEFINE_PROFILE(unst_F_inlet,thread,position) {

real t,tt,fp;

real w=1.0;

int n2=35;

int i,ii;

face_t f;

real x[36]={0.0,0.01395,0.0279,0.0391,0.1313,0.1564,0.1788,0 .1927,0.2067,0.2207,0.2318,0.2486,0.2626,0.2821,0. 3184,0.352,0.3827,0.4106,0.4469,0.4665,0.4804,0.49 72,0.5168,0.5447,0.5698,0.6034,0.6341,0.676,0.7263 ,0.7682,0.7933,0.8296,0.8687,0.9106,0.9525,1.0};

real y[36]={3.0,4.66925,9.3385,28.0156,210.1167,272.3735,348 .6381,404.6693,445.1362,463.8132,473.1518,473.1518 ,459.144,423.3463,365.7588,303.5019,236.5759,166.5 37,99.6109,68.4825,49.8054,40.4669,48.249,76.2646, 99.6109,118.2879,136.965,149.4163,143.1907,130.739 3,105.8366,73.1518,48.249,23.3463,9.3385,3.0};

begin_f_loop(f,thread)

{

t=RP_Get_Real("flow-time");

tt=t-floor(t/w)*w;/*w mean the period time*/

fp=b_spline_f(x,y,tt,n2);/*This is the interplation function. You should write it additionally*/

F_PROFILE(f,thread,position)=fp;

}

end_f_loop(f,thread) }

John, thank you very much for helping me.

Try this link (tutorials of CFX, ICEM CFD, and Fluent 6.1. Fluent 6.1 includes meshes, PDF files, and much more):

http://www.4shared.com/dir/8279926/7..._ICEM_etc.html

John, i have a doubt.

Is x[36] the x component velocity or time in seconds?

real x[36]={0.0,0.01395,0.0279,0.0391,0.1313,0.1564,0.1788,0 .1927,0.2067,0.2207,0.2318,0.2486,0.2626,0.2821,0. 3184,0.352,0.3827,0.4106,0.4469,0.4665,0.4804,0.49 72,0.5168,0.5447,0.5698,0.6034,0.6341,0.676,0.7263 ,0.7682,0.7933,0.8296,0.8687,0.9106,0.9525,1.0};

Is y[36] the x component velocity applied at inlet?

real y[36]={3.0,4.66925,9.3385,28.0156,210.1167,272.3735,348 .6381,404.6693,445.1362,463.8132,473.1518,473.1518 ,459.144,423.3463,365.7588,303.5019,236.5759,166.5 37,99.6109,68.4825,49.8054,40.4669,48.249,76.2646, 99.6109,118.2879,136.965,149.4163,143.1907,130.739 3,105.8366,73.1518,48.249,23.3463,9.3385,3.0};

Thank you,Rogerio. x[36] is time in seconds, y[36] is the corresponding velocity.

Could y[36) be a heat flux in [W m^-2] ?

Can I use the DEFINE_PROFILE(unst_F_inlet,thread,position) macro to impose my heat flux varying in the time?

My geometry is a solid domain and i´m imposing a heat flux as a boundary conidition, and not as an inlet boundary condition.

Thanks again!

No problem, you can use DEFINE_PROFILE to define your boundary conditon.

Hi John,

I tried compiling the file.C, but it appeared an error. When I interpreted the code.c, the compiler didn´t find the b_spline_f function. Do you know how to solve this problem?

Any ideas to help me?

Thanks.

#include "udf.h"

DEFINE_PROFILE(unst_F_inlet, thread, position) {

real t,tt,fp; real w=1.0; int n2=35; int i,ii; face_t f;

real x[36]={0.0,0.01395,0.0279,0.0391,0.1313,0.1564,0.1788,0 .1927,0.2067,0.2207,0.2318,0.2486,0.2626,0.2821,0. 3184,0.352,0.3827,0.4106,0.4469,0.4665,0.4804,0.49 72,0.5168,0.5447,0.5698,0.6034,0.6341,0.676,0.7263 ,0.7682,0.7933,0.8296,0.8687,0.9106,0.9525,1.0}; real y[36]={3.0,4.66925,9.3385,28.0156,210.1167,272.3735,348 .6381,404.6693,445.1362,463.8132,473.1518,473.1518 ,459.144,423.3463,365.7588,303.5019,236.5759,166.5 37,99.6109,68.4825,49.8054,40.4669,48.249,76.2646, 99.6109,118.2879,136.965,149.4163,143.1907,130.739 3,105.8366,73.1518,48.249,23.3463,9.3385,3.0};

begin_f_loop(f, thread) {

t= RP_Get_Real("flow-time");

tt=t-floor(t/w)*w;/*w mean the period time*/

fp=b_spline_f(x,y,tt,n2);/*This is the interplation function. You should write it additionally*/

F_PROFILE(f, thread, position) = fp; } end_f_loop(f, thread)

}

That's right. The file.c cannot run directly even as the annotation in C file: "/*This is the interplation function. You should write it additionally*/". The interplation function isnot pivotal issue. I think that you should selelct any appropriate piecewise interpolations to your problem. Certainly, if you want, I will paste mine in here for you.

Hi ,

If i use an equation, will it be like showed below?

/************************************************** ******************** unsteady.c UDF for specifying a transient velocity profile boundary condition ************************************************** *********************/ #include "udf.h" DEFINE_PROFILE(unsteady_velocity, thread, position) { face_t f; real t = CURRENT_TIME; begin_f_loop(f, thread) { F_PROFILE(f, thread, position) = 20. + 5.0*sin(10.*t); } end_f_loop(f, thread) } c Fluent Inc. January 22, 2003 11-7

Yes. You should only alter the equation to yours.