WaterPy

UPF_moody_f(): Friction loss according to Moody chart

About:

Calculate the friction loss in a pipe, with uniform flow according to the Moody chart.
This function is applied to laminar and turbulent flow, i.e., to all the range of Reynolds number.

Source: Wikipedia

Module: UniformPressurizedFlow

Function: UPF_moody_f(q,e,t,s,d)

Definition of variables:

q, flow - m3/s;
e, pipe roughness - m;
t, temperature - ºC;
s, salinity - g/kg;
d, internal diameter - m.

Sample code:

from UniformPressurizedFlow import*

q = 0.01        #(m3/s)
e = 0.000003    #(m)
t = 15          #(oC)
s = 2.5         #(g/kg)
d = 0.75        #(m)

f = UPF_moody_f(q,e,t,s,d)

print("f:",f, "m/m")

Result:

f: 0.02783272130932784 m/m

UPF_laminarflow_f(): Friction loss for laminar flow

About:

Calculate the friction loss in a pipe, with uniform flow for laminar flow $(Re \leq 2000)$.

\begin{equation} f = \frac{Re}{64} \end{equation}

Where,

Re, Reynolds Number » WATER_reynoldsnumber_re().

Module: UniformPressurizedFlow

Function: UPF_laminarflow_f(q,t,s,d)

Definition of variables:

q, flow - m3/s;
e, pipe roughness - m;
t, temperature - ºC;
s, salinity - g/kg;
d, internal diameter - m.

Sample code:

from UniformPressurizedFlow import*
from WaterProperties import*

q = 0.001       #(m3/s)
d = 0.75        #(m)
t = 15          #(oC)
s = 2.5         #(g/kg)

re = WATER_reynoldsnumber_re(q,d,t,s)
f = UPF_laminarflow_f(q,t,s,d)

Result:

Re: 1496.0351140845949
f: 0.042779744537721494 m/m

WATERCHEM_rsi(): Ryznar Stability Index (RSI)

About:

Calculate the Ryznar Stability Index (RSI).
\begin{equation} RSI = 2 \times pH_s - pH \end{equation}

Module: WaterChemistry

Function: WATERCHEM_rsi(t,ph,tds,ca,hco3)

Parameters:

t, temperature - ºC;
ph, water pH
tds, Total Dissolved Solids - mg/l;
ca, concentration of calcium hardness, mg Ca/liter;
hco3, concetration of HCO3- (alkalinity), mg CaCO3/liter.

Sample code:

from WaterChemistry  import *

ph = 7.7    # water pH
tds = 300   # mg TDS/liter
ca = 50     # mg Ca/liter
hco3 = 100  # mg CaCo3/liter (Alkalinity)
t = 20      # oC

rsi = WATERCHEM_rsi(t,ph,tds,ca,hco3)

print("RSI:",rsi)

Result:

RSI: 8.128539459578171

WATERCHEM_lsi(): Langelier Saturation Index (LSI)

About:

Calculate the Langelier Saturation Index (LSI).
\begin{equation} LSI = pH - pH_s \end{equation}

Module: WaterChemistry

Function: WATERCHEM_lsi(t,ph,tds,ca,hco3)

Parameters:

t, temperature - ºC;
ph, water pH
tds, Total Dissolved Solids - mg/l;
ca, concentration of calcium hardness, mg Ca/liter;
hco3, concetration of HCO3- (alkalinity), mg CaCO3/liter.

Sample code:

from WaterChemistry  import *

ph = 7.7    # water pH
tds = 300   # mg TDS/liter
ca = 50     # mg Ca/liter
hco3 = 100  # mg CaCo3/liter (Alkalinity)
t = 20      # oC

lsi = WATERCHEM_lsi(t,ph,tds,ca,hco3)

print("LSI:",lsi)

Result:

LSI: -0.21426972978908498

WATERCHEM_phscalcium(): Saturation pH for calcium carbonate

About:

Calculate the saturation pH for calcium carbonate.

\begin{equation} pH_s = pK'_2 + pCa^{2+}-pK'_s -log(2 \times \left[Alk \right]) -log\gamma_m \end{equation} \begin{equation}

Module: WaterChemistry

Function: WATERCHEM_phscalcium(t,tds,ca,hco3)

Parameters:

t, temperature - ºC;
tds, Total Dissolved Solids - mg/l;
ca, concentration of calcium hardness, mg Ca/liter;
hco3, concetration of HCO3- (alkalinity), mg CaCO3/liter.

Sample code:

from WaterChemistry  import *

tds = 300   # mg TDS/liter
ca = 50     # mg Ca/liter
hco3 = 100  # mg CaCo3/liter (Alkalinity)
t = 20      # oC

phs = WATERCHEM_phscalcium(t,tds,ca,hco3)

print("phs:",phs)

Result:

phs: 7.914650556552682

HYD_scs_hydrograph(): Flow hydrograph according to SCS

About:

Calculate a watershed flow hydrograph according to Soil Conservation Service (SCS).

©WETpython, 2015

Module: Hydrology

Function: HYD_scs_hydrograph(l,s,area,p)

Parameters:

l, river lenght - m;
s, river slope - m/m;
area, watershed area, m2;
p, runoff rain, mm.

Sample code:

from Hydrology import *

l = 69200 # (m)
s = 0.00387 #(m/m)
area = 225*10**6 #m2

# runoff rain (effective rain), mm
p = [16.0,24.0,43.0,19.0,14.0]

(d,hydrogram,volume) = HYD_scs_hydrograph(l,s,area,p)

print("Unit excess rainfall:", d, "h")
print("hydrograph volume:", volume, "m3")
time = 0.0
print ("***Hydrograph***")
for i in range(len(hydrogram)):
    print("time (h) | hydrogram (h|m3/s) :",time,"|", hydrogram[i])
    time += d

Result:

Unit excess rainfall: 1.925815112733541 h
Hydrograph volume: 80444341.16650842 m3
***Hydrograph***
time (h) | hydrogram (h|m3/s) : 0.0 | 0.0
time (h) | hydrogram (h|m3/s) : 1.925815112733541 | 15.482968124128494
time (h) | hydrogram (h|m3/s) : 3.851630225467082 | 54.19038843444973
time (h) | hydrogram (h|m3/s) : 5.777445338200623 | 134.5082855783663
time (h) | hydrogram (h|m3/s) : 7.703260450934164 | 233.21220736968544
time (h) | hydrogram (h|m3/s) : 9.629075563667705 | 345.46372626961704
time (h) | hydrogram (h|m3/s) : 11.554890676401246 | 433.24022142805944
time (h) | hydrogram (h|m3/s) : 13.480705789134788 | 484.0249981939473
time (h) | hydrogram (h|m3/s) : 15.40652090186833 | 468.61437448410146
time (h) | hydrogram (h|m3/s) : 17.33233601460187 | 423.3893563591242
time (h) | hydrogram (h|m3/s) : 19.258151127335413 | 356.4171629087126
time (h) | hydrogram (h|m3/s) : 21.183966240068955 | 289.20068452552
time (h) | hydrogram (h|m3/s) : 23.109781352802496 | 221.98420614232742
time (h) | hydrogram (h|m3/s) : 25.035596465536038 | 154.7677277591348
time (h) | hydrogram (h|m3/s) : 26.96141157826958 | 93.29837155411423
time (h) | hydrogram (h|m3/s) : 28.88722669100312 | 43.973814835861376
time (h) | hydrogram (h|m3/s) : 30.813041803736663 | 15.38082330071036
time (h) | hydrogram (h|m3/s) : 32.738856916470205 | 3.083601692071024
time (h) | hydrogram (h|m3/s) : 34.66467202920374 | 0.0

HYD_scs_duh(): Synthetic Dimensionless Unit Hydrograph according to SCS

About:

Calculate the Synthetic Dimensionless Unit Hydrograph according to Soil Conservation Service (SCS).

\begin{equation} T_l = 0.6 \times T_c \end{equation} \begin{equation} T_p = \frac{D}{2} + T_l \end{equation} \begin{equation} T_r = 1.67 \times T_p \end{equation} \begin{equation} T_b = T_p + T_b \end{equation} \begin{equation} D = 0.133 \times T_c \end{equation} \begin{equation} q_p = \frac{2.08 \times 10^{-6} \times A}{T_p} \end{equation} Where,

$T_l$, time lag - $h$

$T_p$, time to peak - $h$

$T_r$, recession limb time - $h$

$T_b$, base time - $h$

$T_c$, concentration time » HYD_kirpich_tc() - $h$

$D$, unit excess rain-fall - $h$

$q_q$, Synthetic Dimensionless Unit Hydrograph peak flow - $\frac{m^3}{s}$

$A$, Watershed area - $m^2$

Module: Hydrology

Function: HYD_scs_duh(l,s,area)

Definition of variables:

l, river lenght - m;
s, river slope - m/m;
area, watershed area, m2.

Sample code:

from Hydrology import *

l = 69200 # (m)
s = 0.00387 #(m/m)
area = 225*10**6 #(m2)

(tc, d,tp,tr,qp, duh) = HYD_scs_duh(l,s,area)

print("tc:", tc, "h") # concentration time
print("d:", d,"h") #
print("tp:", tp,"h")
print("tr:", tr,"h")
print("tb:", tp+tr,"h")
print("qp:", qp,"m3/s")
time = 0.0
print ("***Synthetic Dimensionless Unit Hydrograph***")
for i in range(len(duh)):
    print("time|flow (h|m3/s):",time,"|", duh[i])
    time += d

Result:

tc: 14.479812877695796 h
d: 1.925815112733541 h
tp: 9.650795282984248 h
tr: 16.116828122583694 h
tb: 25.767623405567942 h
qp: 48.49341285118252 m3/s
***Synthetic Dimensionless Unit Hydrograph***
time|flow (h|m3/s): 0.0 | 0.0
time|flow (h|m3/s): 1.925815112733541 | 9.676855077580308
time|flow (h|m3/s): 3.851630225467082 | 19.353710155160616
time|flow (h|m3/s): 5.777445338200623 | 29.030565232740926
time|flow (h|m3/s): 7.703260450934164 | 38.70742031032123
time|flow (h|m3/s): 9.629075563667705 | 48.38427538790154
time|flow (h|m3/s): 11.554890676401246 | 42.76424062705119
time|flow (h|m3/s): 13.480705789134788 | 36.9697166285001
time|flow (h|m3/s): 15.40652090186833 | 31.175192629949013
time|flow (h|m3/s): 17.33233601460187 | 25.380668631397928
time|flow (h|m3/s): 19.258151127335413 | 19.586144632846842
time|flow (h|m3/s): 21.183966240068955 | 13.791620634295757
time|flow (h|m3/s): 23.109781352802496 | 7.997096635744673
time|flow (h|m3/s): 25.035596465536038 | 2.2025726371935885
time|flow (h|m3/s): 26.96141157826958 | 0.0