TKE.py

import pandas as pd
import matplotlib.pyplot as plt
import scipy
import numpy as np
from scipy import integrate
from .uniqueFinder import uniqueFinder

def TKE(data):
    '''
    This function is to calculate turbulent kinetic energy (TKE).
    '''
    data = data.copy()
    data = data[data['DisplacementLDA [V]'] != 0.00]
    data.reset_index(drop=True, inplace=True)

    data = data.sort_values('DisplacementLDA [V]').reset_index(drop=True)
    data = uniqueFinder(data)
    data['depth[cm]'] = data['uniqueDisplacement'].groupby(data['uniqueDisplacement']).transform(lambda x:np.round(-2.4953*x+25.753,2))

    ## Velocity components calcuation
    data['U'] = data['Vel1 [V]'].groupby(data['depth[cm]']).transform(lambda x: 0.096*(data['Vel2 [V]']-x))
    data['V'] = data['Vel1 [V]'].groupby(data['depth[cm]']).transform(lambda x: 0.096*(x+data['Vel2 [V]']))

    ## Velocity fluctuation calcuation
    data['uprime'] = data['U'].groupby(data['depth[cm]']).transform(lambda x: x - x.mean())
    data['vprime'] = data['V'].groupby(data['depth[cm]']).transform(lambda x: x - x.mean())

    data['uu_prime'] = data['uprime']*data['uprime']  ## u'u'
    data['vv_prime'] = data['vprime']*data['vprime']  ## v'v'

    TKE = 0.5*(data['uu_prime'].groupby(data['depth[cm]']).mean()+data['vv_prime'].groupby(data['depth[cm]']).mean()) ### TKE = 1/2*(u'u'+v'v')

    upstreamWL = np.mean(38.01-3.76*data['WaterLevel1 [v]'])
    #print('upStreamWL', upstreamWL)
    downstreamWL = np.mean(36.42-3.8*data['WaterLevel3 [V]'])
    #print('downStreamWL', downstreamWL)
    diffWL = np.abs(upstreamWL - downstreamWL)
    waterDepth = (upstreamWL + downstreamWL)/2

    return TKE, upstreamWL