Differential Equations Preview

d(CA)d(z)=y
d(y)d(z)=k·CADAB
d(CA1)d(z)=y1
d(y1)d(z)=k·CA1DAB
k=0.001
DAB=1.2e-9
err=y0
err1=y10
y0=130
L=0.001
δ=0.0001
CAanal=0.2·cosh(L·(kDAB)0.5·(1zL))cosh(L·(kDAB)0.5)
derr=err1errδ·y0
ynew=y0errderr
Boundaries
z(0)=0
CA(0)=0.2
y(0)=130
CA1(0)=0.2
y1(0)=130.013
z(f)=0.001

Program validated. Ready to Solve.
# Example 25- Boundary Value ODE System
# Diffusion with Reaction
# Verified Final Values: CA = 0.140461, y = 2.76438
# Ref.: Comput. Appl. Eng. Educ. 6: 175-176, 1998

d(CA)/d(z)=y
d(y)/d(z)=k*CA/DAB
d(CA1)/d(z)=y1
d(y1)/d(z)=k*CA1/DAB
k=0.001
DAB=1.2E-9
err=y-0
err1=y1-0
y0=-130
L=.001
delta=0.0001
CAanal=0.2*cosh(L*(k/DAB)^.5*(1-z/L))/(cosh(L*(k/DAB)^.5))
derr=(err1-err)/(delta*y0)
ynew=y0-err/derr
z(0)=0
CA(0)=0.2
y(0)=-130
CA1(0)=0.2
y1(0)=-130.013
z(f)=0.001

Calculated values

  Variable ▲ Initial Minimal Maximal Final Value
1CA0.20.14040.20.14046057
2CA10.20.14040.20.14044568
3CAanal0.20.13830.20.13827264
4derr111.4461.4464177
5err-130-1302.7642.7643828
6err1-130-1302.7462.7455795
7y-130-1302.7642.7643828
8y1-130-1302.7462.7455795
9ynew-5.227e-11-131.9-5.227e-11-131.9112
10z000.0010.001
Chart 1
Chart
Chart 2
Chart

Data Table (33 records)


#zCAyCA1y1errerr1CAanalderrynew
100.2-1300.2-130.013-130-130.0130.21-5.2267524e-11
20.0000060.199223-129.001940.19922292-129.01494-129.00194-129.014940.199211521.000015-0.99999
30.0000310.19604956-124.88470.19604915-124.89771-124.8847-124.897710.19599031.0004004-5.165288
40.000064333330.19197686-119.495860.19197603-119.50888-119.49586-119.508880.191853841.001725-10.709912
50.000097666660.18808194-114.217670.18808065-114.23073-114.21767-114.230730.187895031.0039772-16.234783
60.0001310.18436117-109.045250.18435946-109.05835-109.04525-109.058350.184110211.007159-21.729847
70.000164333340.18081112-103.973810.18080898-103.98695-103.97381-103.986950.180495871.0112734-27.185263
80.000197666670.17742851-98.998640.17742592-99.01185-98.99864-99.011850.177048681.0163243-32.591484
90.0002310.17421019-94.115140.17420717-94.12843-94.11514-94.128430.173765441.0223162-37.939304
100.000264333330.1711532-89.31880.17114973-89.332184-89.3188-89.3321840.170643091.0292549-43.21994
110.000297666670.16825469-84.605160.16825077-84.61865-84.60516-84.618650.167678771.0371467-48.425068
120.0003310.16551198-79.969880.16550761-79.983475-79.96988-79.9834750.164869711.0459988-53.546875
130.000364333330.16292255-75.408640.16291772-75.42236-75.40864-75.422360.162213331.0558195-58.5781
140.000397666680.16048397-70.917230.16047868-70.93109-70.91723-70.931090.159707141.066618-63.512062
150.0004310.158194-66.4914860.15818825-66.50551-66.491486-66.505510.157348861.0784041-68.3427
160.000464333340.15605052-62.1273160.1560443-62.141502-62.127316-62.1415020.155136271.0911888-73.06456
170.000497666650.15405154-57.8206750.15404484-57.83504-57.820675-57.835040.153067351.1049839-77.67284
180.0005310.15219522-53.5675770.15218803-53.582134-53.567577-53.5821340.151140151.1198022-82.16336
190.000564333340.15047981-49.3640820.15047215-49.378845-49.364082-49.3788450.149352921.1356575-86.5326
200.000597666660.14890376-45.2062950.1488956-45.22128-45.206295-45.221280.147703991.1525644-90.77764
210.0006310.1474656-41.0903740.14745693-41.10559-41.090374-41.105590.146191841.1705387-94.89619
220.000664333350.14616399-37.0124970.1461548-37.02796-37.012497-37.027960.144815041.1895967-98.88651
230.000697666660.14499772-32.96890.14498802-32.984623-32.9689-32.9846230.143572361.2097564-102.74749
240.0007310.14396572-28.9558260.1439555-28.97183-28.955826-28.971830.142462611.2310362-106.47849
250.000764333350.14306703-24.9695680.14305627-24.985863-24.969568-24.9858630.14148481.2534561-110.07942
260.000797666670.14230083-21.0064320.14228952-21.023033-21.006432-21.0230330.1406381.2770365-113.55064
270.0008310.14166638-17.0627460.14165452-17.07967-17.062746-17.079670.139921411.3017997-116.89295
280.000864333360.14116313-13.1348620.1411507-13.152123-13.134862-13.1521230.139334411.3277681-120.10757
290.00089766670.1407906-9.219140.14077757-9.236755-9.21914-9.2367550.138876421.3549662-123.19604
300.0009310.14054842-5.31195550.14053482-5.32994-5.3119555-5.329940.138547031.3834189-126.16027
310.000964333360.14043641-1.40968940.1404222-1.4280604-1.4096894-1.42806040.138345941.4131527-129.00246
320.00099766660.140454432.49127130.14043962.47249672.49127132.47249670.138272961.444195-131.72502
330.0010.140460572.76438280.140445682.74557952.76438282.74557950.138272641.4464177-131.9112
Raw data presented with 33 records.

Constant Values

ConstantkDABy0Ldelta
Value0.0011.2e-9-1300.0010.0001

Settings and Hints

 Name/SourceValueType
1 Total number of equations 14 Setting
2 Number of differential equations 4 Setting
3 Number of explicit equations 10 Setting
4 Reporting digits 10 Setting
5 Minimal License Free - 2 Setting
6 Elapsed time 0.076 ms Setting
7 Solution method RKF_45 Setting
8 Step size guess. h 0.000011666667 Setting
9 Truncation error tolerance. eps 0.000001 Setting
10 Good steps 33 Setting
11 Bad steps 0 Setting
12 Calculated Intermediate data points 50 Setting
13 Version 7.0.73 Setting
14 #@chart_size = 428,300 Default (array2)
15 #@chart_interpolate = 2 Default (integer)
16 #@chart_curve_width = 2 Default (integer)
17 #@report_fix_digits = 8 Default (integer)
18 #@report_show_charts = true Default (boolean)
19 #@report_show_data_points = true Default (boolean)
20 #@report_show_intermediate_data_points = true Default (boolean)
21 #@report_show_source = true Default (boolean)
22 #@report_show_header = false Default (boolean)
23 #@report_show_settings = true Default (boolean)
24 #@chart_all_curves = false Default (boolean)
25 #@chart_curves_stiff_grouping_percent = 50 Default (integer)
26 #@chart_y_curves = Default (array2)
27 #@chart_log_scales = 000 Default (string)

Messages

 SeverityDescription
1Info-Infor- Differential variables (4) ; CA, y, CA1, y1
2Info-Infor- Explicit variables (10) ; k, DAB, err, err1, y0, L, delta, CAanal, derr, ynew
3Info-Infor- Independent variable = z

Source

# Example 25- Boundary Value ODE System
# Diffusion with Reaction
# Verified Final Values: CA = 0.140461, y = 2.76438
# Ref.: Comput. Appl. Eng. Educ. 6: 175-176, 1998

d(CA)/d(z)=y
d(y)/d(z)=k*CA/DAB
d(CA1)/d(z)=y1
d(y1)/d(z)=k*CA1/DAB
k=0.001
DAB=1.2E-9
err=y-0
err1=y1-0
y0=-130
L=.001
delta=0.0001
CAanal=0.2*cosh(L*(k/DAB)^.5*(1-z/L))/(cosh(L*(k/DAB)^.5))
derr=(err1-err)/(delta*y0)
ynew=y0-err/derr
z(0)=0
CA(0)=0.2
y(0)=-130
CA1(0)=0.2
y1(0)=-130.013
z(f)=0.001