Lecture 7 (Stream Velocities)

47問 • 1年前

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通報

問題一覧

speed of the water in the stream

Stream Velocity

unit of speed velocity

distance per time

instrument for stream velocity

Floats, Current Meters

most reliable instrument for measuring stream flow

Current Meter

limited to velocity measurements in artificial channel

Float

Current meters measure ______ _____ in stream while float only measure _______ ______

subsurface velocity, surface velocity

Current meter can accurately determined at nearly ________ in the crosssection of the stream

all points

Float Stretch - Cross Section -

straight, uniform

Current Meter Stretch - Cross Section -

irregular, variable

measurement of stream velocity by floats is well suited for ___________ work, in determining _________, or in locating _______ ____

reconnaissance, flood velocity, gaging stations

Classification of Floats

Surface, Subsurface, Rod

these floats usually are not recovered by the time they are used

Surface

intended to measure stream surface velocities and is particularly suitable for rough determinations of velocity

Surface Float

common coefficient range for surface float

0.80-0.90

in the form of double float

Subsurface

unsuitable for use in small shallow stream

Subsurface

used of lightweight or hollowed materials in assorted shapes

Surface

what does rod floats direction measures?

mean velocity

is weighted at the bottom to allow it to float vertically upright with only a short length exposed above the surface of the water.

Rod

In current meter, there are various forms that differ considerably in details but the instrument consists essentially of a _____ with ____ or ____ so constructed that the impact of flowing water causes the wheel to revolved

wheel, cups, vanes

shape of lead weight of current meter

torpedo

common weight of leads

6.8 kg

In vertical axis meter, the rotor used is fitted with ___-shaped vanes which either _____ or ______.

cup, conical, curved

rotation normal to the direction of stream flow.

Vertical Axis Meter

In horizontal axis meter, the rotation of the wheel is caused by the direct ____ and _____ of the water acting upon the vanes.

impulse, pressure

In horizontal axis meter, rotor is fitted with ____ or ______ shaped vanes.

spiral, helicoidal

Classification of Vertical Axis Meter

Pygmy, Price, Vane

consist of wheel with 6 conical cups fastened to a vertical shaft

Price

Price Meter is equipped with ____ or mechanism of indicating each ___ revolution of the wheel

pentacount, fifth

price meter is used in measuring streams exceeding ___ _/_

2 m/s

used only for wading measurements

Pygmy

vane meter cannot accurately measur velocity lower than __ /

0.5 m/s

what is vane meter used for?

measuring under ice cover, measuring from boat

Classification of Horizontal Axis Meter

Hoff, Ott, Haskell

Hoff meter is fitted with lightweight ____-_____ propeller with ___or___ blades

hard-rubber, three, four

German made precision instrument

Ott

____ automatically registers ____

Ott Meter, velocity component of current flow

In Haskell, propeller with different ___ __ may be used

blade pitches

Haskell - _____ Ott - measurement of current in ___ ____ Hoff - measurement in ____

reconnaissance, high velocity, shallow stream

conical shaped screw propeller

Haskell

most precise method of determining mean velocity

Vertical Velocity Curve

suitable for use under unusual conditions of flow and could also be used as a basis of comparison

Vertical Velocity Curve

in two point method, velocity of the stream is observed at ____ and ____ of the depth below the water surface

two tenths, eight tenths

any vertical velocity-curve the average of the abscissa readings at _____ and ____ depth below the surface gives the mean velocity in the vertical

0.2114, 0.7886

Two Point Method should not be used in:

depth less than 0.60m, shallow stream

is positioned at the depth of the expected thread of mean velocity

Single Point

Lowered slowly and at a uniform rate along the vertical from the water surface to the stream bed

Integration

Lecture 1 Part 1

Lecture 1 Part 1

Lecture 1 Part 2

Lecture 1 Part 2

Lecture 1 Part 3

Lecture 1 Part 3

GEOE (Lecture 1-3)

GEOE (Lecture 1-3)

Laws Related to Geodetic Engineering

ユーザ名非公開 · 31問 · 1年前

Laws Related to Geodetic Engineering

31問 • 1年前

ユーザ名非公開

Geodetic Engineering Laws

ユーザ名非公開 · 10問 · 1年前

Geodetic Engineering Laws

Midterms

Midterms

Lesson 6

Lesson 6

Lesson 7A

Lesson 7A

Lesson 7B

Lesson 7B

Lesson 7C

Lesson 7C

Lecture 2

Lecture 2

Lecture 1

Lecture 1

Lecture 2

Lecture 2

Lesson 1

ユーザ名非公開 · 28問 · 11ヶ月前

Lesson 1

28問 • 11ヶ月前

ユーザ名非公開

History

ユーザ名非公開 · 10問 · 11ヶ月前

History

Lesson 2

Lesson 2

Lesson 3

ユーザ名非公開 · 38問 · 11ヶ月前

Lesson 3

38問 • 11ヶ月前

ユーザ名非公開

問題一覧

speed of the water in the stream

Stream Velocity

unit of speed velocity

distance per time

instrument for stream velocity

Floats, Current Meters

most reliable instrument for measuring stream flow

Current Meter

limited to velocity measurements in artificial channel

Float

Current meters measure ______ _____ in stream while float only measure _______ ______

subsurface velocity, surface velocity

Current meter can accurately determined at nearly ________ in the crosssection of the stream

all points

Float Stretch - Cross Section -

straight, uniform

Current Meter Stretch - Cross Section -

irregular, variable

measurement of stream velocity by floats is well suited for ___________ work, in determining _________, or in locating _______ ____

reconnaissance, flood velocity, gaging stations

Classification of Floats

Surface, Subsurface, Rod

these floats usually are not recovered by the time they are used

Surface

intended to measure stream surface velocities and is particularly suitable for rough determinations of velocity

Surface Float

common coefficient range for surface float

0.80-0.90

in the form of double float

Subsurface

unsuitable for use in small shallow stream

Subsurface

used of lightweight or hollowed materials in assorted shapes

Surface

what does rod floats direction measures?

mean velocity

is weighted at the bottom to allow it to float vertically upright with only a short length exposed above the surface of the water.

Rod

wheel, cups, vanes

shape of lead weight of current meter

torpedo

common weight of leads

6.8 kg

In vertical axis meter, the rotor used is fitted with ___-shaped vanes which either _____ or ______.

cup, conical, curved

rotation normal to the direction of stream flow.

Vertical Axis Meter

In horizontal axis meter, the rotation of the wheel is caused by the direct ____ and _____ of the water acting upon the vanes.

impulse, pressure

In horizontal axis meter, rotor is fitted with ____ or ______ shaped vanes.

spiral, helicoidal

Classification of Vertical Axis Meter

Pygmy, Price, Vane

consist of wheel with 6 conical cups fastened to a vertical shaft

Price

Price Meter is equipped with ____ or mechanism of indicating each ___ revolution of the wheel

pentacount, fifth

price meter is used in measuring streams exceeding ___ _/_

2 m/s

used only for wading measurements

Pygmy

vane meter cannot accurately measur velocity lower than __ /

0.5 m/s

what is vane meter used for?

measuring under ice cover, measuring from boat

Classification of Horizontal Axis Meter

Hoff, Ott, Haskell

Hoff meter is fitted with lightweight ____-_____ propeller with ___or___ blades

hard-rubber, three, four

German made precision instrument

Ott

____ automatically registers ____

Ott Meter, velocity component of current flow

In Haskell, propeller with different ___ __ may be used

blade pitches

Haskell - _____ Ott - measurement of current in ___ ____ Hoff - measurement in ____

reconnaissance, high velocity, shallow stream

conical shaped screw propeller

Haskell

most precise method of determining mean velocity

Vertical Velocity Curve

suitable for use under unusual conditions of flow and could also be used as a basis of comparison

Vertical Velocity Curve

in two point method, velocity of the stream is observed at ____ and ____ of the depth below the water surface

two tenths, eight tenths

any vertical velocity-curve the average of the abscissa readings at _____ and ____ depth below the surface gives the mean velocity in the vertical

0.2114, 0.7886

Two Point Method should not be used in:

depth less than 0.60m, shallow stream

is positioned at the depth of the expected thread of mean velocity

Single Point

Lowered slowly and at a uniform rate along the vertical from the water surface to the stream bed

Integration