Velocity scalar and velocity vector fields are flipped

[WJPeace1]

The attached files show a velocity vector and a velocity scalar field in the same plane at the same location. As seen by the heatmap, the velocities are flipped about the centre of the image. This is true for all data in any axis view.

[DanW97]

Oops!

I will investigate.

[DanW97]

Hi @WJPeace1 can you share the script you were using for the plots?

[WJPeace1]

Hi @DanW97, here you go!

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Velocity Fields

from math import inf from re import template import numpy as np import plotly as p import plotly.express as pexp import plotly.graph_objects as go import up4 from collections import defaultdict

Import data

hdf_name = '16_190_trajectories.hdf5'

Extract values for plots and tip speed calculation

filename_final = hdf_name.split(".hdf5")[0] variables = filenamefinal.split("")

if int(variables[0]) > 0: vvm = str(int(variables[0])/10) + str("VVM") else: vvm = str("Ungassed") print(vvm)

speed = int(variables[1]) speed_rpm = str(int(variables[1])) + str("RPM") statement = str(vvm) + str(" - ") + str(speed_rpm) tip_speed = (2 np.pi speed (1/60) 0.033) save_statement = str(speedrpm) + str("") + str(vvm)

Data Load-In

data = up4.Data(hdf_name)

Dimension Statistics

dim = data.dimensions() xmin = dim['xmin'] xmax = dim['xmax'] ymin = dim['ymin'] ymax = dim['ymax'] zmin = dim['zmin'] zmax = dim['zmax'] xmed = (xmin + xmax) 0.5 # midpoint in x-axis ymed = (ymin + ymax) 0.5 # midpoint in y-axis zimpeller = zmin + ((zmax - zmin)/3) # impeller level in the tank

Forming a Grid

cx = 25 cy = cx cz = cx

grid = up4.Grid.cartesian3d_from_data(data, cells = [cx,cy,cz]) # cartesian co-ordinates field = data.velocityfield(grid) xpos,ypos,zpos = field.cell_positions()

CENTRE SLICES

YMed Slice

vel_slice_ymed = np.rot90(field.slice_pos(axis = 1, position = ymed),3) fig = go.Figure() fig.add_trace(go.Heatmap(z = vel_slice_ymed, zmin = 0)) fig.update_layout( title = str(f"{statement}" + ": Central Slice Velocity Field: XZ Plane "), title_x = 0.5, width = 1000, height = 1000, xaxis_title = " r/R ", yaxis_title = " z/H ", xaxis = dict( tickmode = 'array', tickvals = [0,int(cx/4),int(cx/2),int((3cx)/4),int(cx-1)], ticktext = [" -1 ", " -0.5 "," 0 ", " 0.5 "," 1 "], ), yaxis = dict( tickmode = 'array', tickvals = [0,int(cx/4),int(cx/2),int((3cx)/4),int(cx-1)], ticktext = [" 0 ", " 0.25 "," 0.5 ", " 0.75 "," 1 "], ), template = "plotly_white", font = dict( family = "Arial", size = 20, color = "black", ) )

fig.show()

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