Analysis of thermal effects on body temperature distribution of sonic nozzles

2018 ◽  
Author(s):  
Peijuan Cao ◽  
Chao Wang ◽  
Hongbing Ding ◽  
Xiaotong Wang
Keyword(s):  
Temperature Distribution ◽  
Body Temperature ◽  
Thermal Effects

scholarly journals A TWO-DIMENSIONAL THERMODYNAMIC MODEL TO PREDICT HEART THERMAL RESPONSE DURING OPEN CHEST PROCEDURES

2016 ◽  
Vol 15 (1) ◽  
pp. 44
Author(s):  
F. G. Dias ◽  
J. V. C. Vargas ◽  
M. L. Brioschi
Keyword(s):  
Cardiac Surgery ◽  
Temperature Distribution ◽  
Thermodynamic Model ◽  
Thermal Effects ◽  
Computational Simulation ◽  
Thermal Response ◽  
Cardiac Response ◽  
The Finite Element Method ◽  
Thermal Distribution ◽  
Open Chest

In this work, the temperature distribution of the heart in an open chest surgery scenario is studied. It is also evaluated the cardiac thermal effects of the injection of a cooling liquid in the aorta root, which is used in infrared thermography. The finite element method was used to develop a model that predicts the temperature distribution modification in a 2-dimensional slice of the heart. This thermodynamic model allows the computational simulation of the thermal cardiac response to open chest procedures, which are required by cardiac surgery. The influence of several operating parameters (e.g., coronary flow rate, temperature) on the resulting thermal distribution is analyzed. Therefore, this analysis allows the identification of parameters that could be controlled to minimize the loss of energy, and consequently, avoiding the hazardous thermal distribution that could put the heart in danger during cardiac surgery.

Analysis of Microheat Pipes With Axial Conduction in the Solid Wall

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Yew Mun Hung ◽  
Kek-Kiong Tio
Keyword(s):  
Temperature Distribution ◽  
Heat Transport ◽  
Thermal Effects ◽  
Solid Wall ◽  
Flow Characteristics ◽  
Operating Conditions ◽  
Working Fluid ◽  
Transport Capacity ◽  
Axial Temperature ◽  
Energy Equations

A one-dimensional, steady-state model of a triangular microheat pipe (MHP) is developed, with the main purpose of investigating the thermal effects of the solid wall on the heat transport capacity of an MHP. The energy equation of the solid wall is solved analytically to obtain the axial temperature distribution, the average of which over the entire length of the MHP is simply its operating temperature. Next, the liquid phase is coupled with the solid wall by a heat transfer coefficient. Then, the continuity, momentum, and energy equations of the liquid and vapor phases are, together with the Young–Laplace equation, solved numerically to yield the heat and fluid flow characteristics of the MHP. The heat transport capacity and the associated optimal charge level of the working fluid are predicted for different operating conditions. Comparison between the models with and without a solid wall reveals that the presence of the solid wall induces a change in the phase change heat transport by the working fluid, besides facilitating axial heat conduction in the solid wall. The analysis also highlights the effects of the thickness and thermal conductivity of the solid wall on its axial temperature distribution. Finally, while the contribution of the thermal effects of the solid wall on the heat transport capacity of the MHP is usually not dominant, it is, nevertheless, not negligible either.

Thermoelastic Whirling Analysis of Cylinders During Grinding

2009 ◽  
Author(s):  
Erno Keskinen ◽  
Timo Karvinen ◽  
Vladimir Dospel ◽  
Mika To¨ho¨nen ◽  
Teppo Syrja¨nen ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Thermal Effects ◽  
Time Integration ◽  
Interaction Mechanism ◽  
Thermoelastic Problem ◽  
Work Piece ◽  
Bending Vibrations ◽  
Thermal Deformations ◽  
Eigenfunction Basis ◽  
Modal Coordinates

Cylinder grinding has been the subject for an intensive research, because delay-type resonances, commonly known as chatter-vibrations, have been reason for serious surface quality problems in industry [1]. As a result of this activity there is available a simulation platform, on which the complete grinding process including delay-resonances can be driven [2]. This platform consists of models for the grinder, for the cylindrical work piece and for the stone-cylinder grinding contact. The elastic cylinder model is based on analytical eigenfunctions in bending vibrations, which basis has been used to present the rotordynamic equations of cylinder in modal coordinates. Stone-cylinder interaction mechanism has been derived by combining the rules of mass and momentum transfer in the material removal process. The contribution of this paper is to update the platform to include the thermal effects of the work body. Following the method to use the eigenfunctions of a non-supported beam to describe the rotordynamic motion of the work body, a promising method could be to use in a similar way the eigenfunctions of a thermally isolated cylinder to solve the temperature distribution of the cylinder. The temperature distribution and terms related to the non-homogeneous boundary conditions will then be the input to the thermoelastic problem. It can be shown that the eigenfunction basis consists of trigonometric functions in axial and circumferential directions while the radial eigenfunctions are Bessel functions. The stone-cylinder interface has to be updated also to include thermal effects. A portion of the mechanical power is transferred to the work piece. The rest goes to the stone, to the material, which is removed and to the cutting coolant. On the other hand, thermal deformations modify the grinding forces, which are loading the work piece. The solution of the coupled thermal and thermoelastic problem will be done in terms of modal coordinates corresponding to the eigenfunction basis. This leads to numerical time integration of two groups of differential equations, the solution of which can be used to perform the temperature distributions and the corresponding thermal deformations.

Thermal Drift of Floated Gyroscopes

1957 ◽  
Vol 24 (4) ◽  
pp. 506-508
Author(s):  
L. E. Goodman ◽  
A. R. Robinson
Keyword(s):  
Temperature Distribution ◽  
Thermal Effects ◽  
Gravitational Force ◽  
Drift Rate ◽  
Force Convection ◽  
Thermal Drift ◽  
Plane Parallel

Abstract When a floated gyroscope is subjected to a temperature distribution which is not symmetrical about a plane parallel to the gravitational force, convection currents tend to rotate the gimbal. The rebalance torque and the free drift rate due to thermal effects are first determined for the case of an exactly centered gimbal. It is then shown that moderate gimbal eccentricity has little influence on thermal drift, and, in fact, reduces thermal rebalance torque.

Semi Analytical Prediction of Automobile Body Temperature Distribution in the Top Coat Paint Oven

2009 ◽  
Author(s):  
P. Hanafizadeh ◽  
B. Sajadi ◽  
M. H. Saidi ◽  
H. Khalkhali ◽  
M. Taherraftar
Keyword(s):  
Temperature Distribution ◽  
Body Temperature ◽  
Thermal Behavior ◽  
The Body ◽  
Transient Temperature ◽  
Analytical Prediction ◽  
Experimental Procedure ◽  
Car Body ◽  
And Performance ◽  
Good Agreement

Automotive industry frequently needs to test new products, according to different production parameters, in order to determine the actual thermal behavior of bodies before mass production is implemented. Numerical simulation of these processes can reduce the very expensive and time consuming experimental procedures. For the drying and hardening process of the top paint applied in the coating process, the body temperature must be raised according to the paint manufacturer regulations. Consequently, prediction of temperature distribution of the car body during various zones of ovens is very vital in the design and performance analysis of the paint dryers. In this research, a novel semi-analytical approach has been used to predict the body temperature variation during the curing process. Considering the energy balance for the body, a set of differential equation has been extracted, depending on the oven zone. These equations can be solved numerically to find the transient temperature profile of the car body. Some parameters in these equations have been achieved by experimental procedure. The results show that the present model predictions are in a good agreement with the experimental data. Therefore, the developed model has a reasonable accuracy and can be used as an efficient robust approach to distinguish overall thermal behavior of the body. These techniques can be used to optimize the design of curing paint oven.

Sign in / Sign up

Export Citation Format

Share Document