scholarly journals CFD Modeling of Aerodynamic Car Brake Cooling System

Author(s):  
Florin-Bogdan MARIN ◽  
Mihaela MARIN

The objective of this experimental research is to identify solutions for an optimal cooling of the disks. The aerothermal brake cooling calculation is used to determine how the brake cooling process evolves. The techniques for simulating the dynamics of the CFD fluid allow us to simulate the cooling of the brakes in air current and then to compare the results obtained in the wind tunnel.

Author(s):  
Marvin Schmidt ◽  
Andreas Schütze ◽  
Stefan Seelecke

Energy saving and environmental protection are topics of growing interest. In the light of these aspects alternative refrigeration principles become increasingly important. Shape memory alloys (SMA), especially NiTi alloys, generate a large amount of latent heat during solid state phase transformations, which can lead to a significant cooling effect in the material. These materials do not only provide the potential for an energy-efficient cooling process, they also minimize the impact on the environment by reducing the need for conventional ozone-depleting refrigerants. Our paper, presenting first results obtained in a project within the DFG Priority Program SPP 1599 “Ferroic Cooling”, focuses on the thermodynamic analysis of a NiTi-based cooling system. We first introduce a suitable cooling process and subsequently illustrate the underlying mechanisms of the process in comparison with the conventional compression refrigeration system. We further introduce a graphical solution to calculate the energy efficiency ratio of the system. This thermodynamic analysis method shows the necessary work input and the heat absorption of the SMA in stress/strain- or temperature/entropy-diagrams, respectively. The results of the calculations underline the high potential of this solid-state cooling methodology.


2013 ◽  
Vol 361-363 ◽  
pp. 1105-1109
Author(s):  
Chun Sheng Shu

Liujiaxia Bridge is a truss stiffening girder suspension bridge which span is 536m, and it is the narrowest suspension bridge with the same scale, so the problems of flutter stability are prominent. Results of wind tunnel test show that its critical velocity cannot meet the requirements without any aerodynamic measures. Based on above considerations, seven kinds of aerodynamic measures are proposed, respectively wind tunnel tests are conducted. The results show that the program, in which the upper central stable board is 1.12m high and the under central stable board is 1.28m high, can meet the requirements. The results of this study provide some references to solving the problem of wind-resistant stability of narrow deck suspension bridge.


Author(s):  
Vlastimil Nejtek ◽  
Jiří Fryč ◽  
Josef Los

Measuring in laboratory conditions was performed with the aim to collect a sufficient quantity of measured data for the qualified application of flat-plate coolers in measuring under real operating conditions. The cooling water tank was filled with tap water; the second tank was filled with water at a temperature equivalent to freshly milked milk. At the same time, pumps were activated that delivered the liquids into the flat-plate cooler where heat energy was exchanged between the two media. Two containers for receiving the run-out liquid were placed on the outputs from the cooler; here, temperature was measured with electronic thermometer and volume was measured with calibrated graduated cylinder. Flow rate was regulated both on the side of the cooling fluid and on the side of the cooled liquid by means of a throttle valve. The measurements of regulated flow-rates were repeated several times and the final values were calculated using arithmetic average. To calculate the temperature coefficient and the amount of brought-in and let-out heat, the volume measured in litres was converted to weight unit. The measured values show that the volume of exchanged heat per weight unit increases with the decreasing flow-rate. With the increasing flow-rate on the throttled side, the flow-rate increases on the side without the throttle valve. This phenomenon is caused by pressure increase during throttling and by the consequent increase of the diameter of channels in the cooler at the expense of the opposite channels of the non-throttled part of the circuit. If the pressure is reduced, there is a pressure decrease on the external walls of opposite channels and the flow-rate increases again. This feature could be utilised in practice: a pressure regulator on one side could regulate the flow-rate on the other side. The operating measurement was carried out on the basis of the results of laboratory measurements. The objective was to determine to what extent the use of flat-plate coolers under specific conditions results in cost reduction and improved milk cooling process. The measurement was performed in several cycles. The first measurement took place in the existing system without the use of the flat-plate cooler. The volume of drawn milk was monitored throughout the milking process along with its temperature, temperature in the tank and electricity consumption of the cooling system. At the second stage, the flat-plate cooler was introduced into the cooling process, which was followed by monitoring the milk and cooling water volume, their temperature, temperature in the tank and electricity consumption of the cooling system. The measured data indicate considerable power cost reduction if upstream flat-plate coolers are applied.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Anan Suebsomran ◽  
Suthep Butdee

This research aims to achieving the effective cooling parameter on the runout table (ROT) of strip steel in hot rolling process. The 2-dimensional transient heat conduction is developed including the external force convection and heat source due to translational motion. The material property, boundary, and initial condition are defined and bounded to model geometry. The strip velocity, cooling water temperature, and external fluid velocity are chosen for the influent parameters during cooling process at ROT. To find the optimality of cooling operating requirement, simulation study is conducted throughout this research. To reach the objective of optimal cooling consumption at ROT, temperature distribution in the strip steel during cooling governs by the form of heat transfer equation. To solve 2-dimensional transient heat conduction by numerical methods, the backward difference formula (BDF) applies to discretization of partial differentiation equation (PDE). The parallel sparse direct linear solver (PARDISO) and conjugate gradients method are comparatively applied to computation in linear algebraic equation. The simulation studies are divided into 12 case studies with three variations subjected to cooling conditions at ROT. From simulation results, the range of such three variations can be identified in relation to economic cooling system and desired quality of products.


1939 ◽  
Vol 43 (346) ◽  
pp. 803-832 ◽  
Author(s):  
Antonio Ferri

Our first phase of activity, at the Guidonia supersonic wind tunnel, was devoted to studying and designing the necessary apparatus for carrying out systematic research. (See Captain Gasperi's paper, read before the Lilienthal Congress in 1937-) This apparatus consisted principally of:—(1)A series of transformer jets, to create the requisite speeds in the test chamber;(2)A balance, to determine the forces exercised by aerodynamic phenomena upon the objects under test;(3)The striometric and interferometric apparatus.The initial study was long and laborious; since we lacked the great help furnished by previous research, which is nearly always forthcoming in similar studies, we had to proceed by means of successive experiments until the apparatus took its final shape. Eventually we evolved a series of jets, a balance and an optical installation which we hope are permanent. These, however, being still under construction, have not yet been tested.


2007 ◽  
Author(s):  
Yong Yi ◽  
Madhusudhana Reddy ◽  
Mark Jarrett ◽  
Pin Shyu ◽  
Cletus Kinsey ◽  
...  

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