Dynamic and Static Characteristics Analysis Study of Hot-Wire Probe in Constant Temperature Model

2013 ◽  
Vol 278-280 ◽  
pp. 735-742
Author(s):  
Qing Yan Wei ◽  
Tian Hong Zhang
Keyword(s):  
Heat Conduction ◽  
Constant Temperature ◽  
Temperature Model ◽  
Static Characteristics ◽  
Hot Wire ◽  
Wire Probe ◽  
Balance Principle ◽  
Characteristics Analysis ◽  
Control Circuits ◽  
Improved Design

Lumped and distributed dynamic/static models of constant temperature hot-wire probe are established according to heat balance principle. Dynamic and static characteristics of hot-wire probe are analyzed in terms of hot-wire probe sizes, control circuit parameters and flow velocity.Simulation results show that reliability and stability of the hot-wire probe depend on bias voltage.The dynamic and static characteristics of hot-wire probe refly on the ratio of length to diameter ratio crucially.Once the ratio exceeds 300, heat conduction terminal loss can be ignored. When over-heating ratio of hot- wire or flow velocity increases, heat conduction terminal loss can be omitted as well .Besides frequency response of hot-wire probe can be improved simultaneously.The above conclusions can provide guidance in the improved design for hot-wire probe and its control-circuits.

Calibration of Constant-Temperature Hot-Wire Anemometers at Low Velocities in Water with Variable Fluid Temperature

1972 ◽  
Vol 94 (1) ◽  
pp. 17-22 ◽  
Author(s):  
K. Hollasch ◽  
B. Gebhart
Keyword(s):  
Experimental Study ◽  
Natural Convection ◽  
Constant Temperature ◽  
Fluid Temperature ◽  
Hot Wire ◽  
Temperature Variations ◽  
Wire Probe ◽  
Temperature Mode

Calibration of hot-wire probes operated in a constant-temperature mode in water at low velocities is discussed. Operation under circumstances where natural convection effects are important is considered. A method of calibrating a constant-temperature hot-wire probe for variations in fluid temperature is presented. The method consists of varying wire overheat during calibration at a constant fluid temperature. A relation is derived analytically relating anemometer output with a variable overheat resistance to anemometer output with fluid temperature variations. An experimental study to verify the analysis is presented.

Self-Aligning Hot-Wire Probe

1967 ◽  
Vol 71 (681) ◽  
pp. 657-658 ◽  
Author(s):  
A. D. Bond ◽  
A. M. Porter
Keyword(s):  
Constant Temperature ◽  
Two Dimensional ◽  
Servo Motor ◽  
Hot Wire ◽  
Turbulence Measurements ◽  
Wire Probe ◽  
Two Dimensional Flow ◽  
The Wire ◽  
Single Constant ◽  
Stream Direction

Summary:—This note describes how a single constant temperature hot wire may be used for measurements of direction, velocity and turbulence in a two-dimensional flow. The wire probe is rotated by a servo motor which automatically sets the wire with its axis either in the stream direction or normal to the flow. The accuracy of setting the wire in the direction of the stream is about , and across the stream is about 1°. If the higher accuracy is demanded the velocity and turbulence measurements require a second setting of the probe, at 90° to the previous one. When less precision is acceptable, the angle, velocity and turbulence measurements may be taken at the single setting, normal to the stream.

Application of a three-sensor hot-wire probe for incompressible flow

AIAA Journal ◽  
1983 ◽  
Vol 21 (6) ◽  
pp. 863-863
Author(s):  
T. L. Butler ◽  
J. W. Wagner
Keyword(s):  
Incompressible Flow ◽  
Hot Wire ◽  
Wire Probe

The proximity hot-wire probe for measuring surface shear in air flows

1995 ◽  
Vol 6 (3) ◽  
pp. 201-206 ◽  
Author(s):  
J.C. Gibbings ◽  
J. Madadnia ◽  
S. Riley ◽  
A.H. Yousif
Keyword(s):  
Hot Wire ◽  
Surface Shear ◽  
Wire Probe ◽  
Measuring Surface ◽  
Air Flows

scholarly journals Simplified Grinding Temperature Model Study

2019 ◽  
Vol 6 (2) ◽  
pp. a1-a7
Author(s):  
N. V. Lishchenko ◽  
V. P. Larshin ◽  
H. Krachunov
Keyword(s):  
Differential Equation ◽  
Heat Conduction ◽  
Heat Source ◽  
Boundary Conditions ◽  
Grinding Temperature ◽  
Temperature Model ◽  
One Dimensional ◽  
Heating And Cooling ◽  
Equation Of Heat Conduction ◽  
The One

A study of a simplified mathematical model for determining the grinding temperature is performed. According to the obtained results, the equations of this model differ slightly from the corresponding more exact solution of the one-dimensional differential equation of heat conduction under the boundary conditions of the second kind. The model under study is represented by a system of two equations that describe the grinding temperature at the heating and cooling stages without the use of forced cooling. The scope of the studied model corresponds to the modern technological operations of grinding on CNC machines for conditions where the numerical value of the Peclet number is more than 4. This, in turn, corresponds to the Jaeger criterion for the so-called fast-moving heat source, for which the operation parameter of the workpiece velocity may be equivalently (in temperature) replaced by the action time of the heat source. This makes it possible to use a simpler solution of the one-dimensional differential equation of heat conduction at the boundary conditions of the second kind (one-dimensional analytical model) instead of a similar solution of the two-dimensional one with a slight deviation of the grinding temperature calculation result. It is established that the proposed simplified mathematical expression for determining the grinding temperature differs from the more accurate one-dimensional analytical solution by no more than 11 % and 15 % at the stages of heating and cooling, respectively. Comparison of the data on the grinding temperature change according to the conventional and developed equations has shown that these equations are close and have two points of coincidence: on the surface and at the depth of approximately threefold decrease in temperature. It is also established that the nature of the ratio between the scales of change of the Peclet number 0.09 and 9 and the grinding temperature depth 1 and 10 is of 100 to 10. Additionally, another unusual mechanism is revealed for both compared equations: a higher temperature at the surface is accompanied by a lower temperature at the depth. Keywords: grinding temperature, heating stage, cooling stage, dimensionless temperature, temperature model.

A Three-Dimensional Analysis of Rotor Wakes

1972 ◽  
Vol 23 (4) ◽  
pp. 285-300 ◽  
Author(s):  
C E Whitfield ◽  
J C Kelly ◽  
B Barry
Keyword(s):  
Dimensional Analysis ◽  
Constant Temperature ◽  
Three Dimensional ◽  
Axial Flow ◽  
Visual Presentation ◽  
Hot Wire ◽  
Three Dimensional Flow ◽  
Dimensional Flow

SummaryMany investigators have studied the aerodynamics of axial flow turbomachinery but none has produced a complete map of the three-dimensional flow behind a rotor row. This is of considerable interest to the aero-acoustician. A system is described which uses a constant temperature hot-wire anemometer to analyse the flow behind such a rotor. Although much information may be extracted by using the technique, its interpretation depends to a large extent on its form of presentation. An analysis of the flow behind a research fan is used as a means of discussing various forms of visual presentation.

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