Browse Topic: Cooling

Items (49)

J2082_202511 (Current)

11/21/2025

This SAE Information Report has been prepared at the request of the SAE Road Vehicle Aerodynamics Forum Committee (RVAC), incorporating material from earlier revisions of the document first prepared by the Standards Committee on Cooling Flow Measurement (CFM).Although a great deal is already known about engine cooling, recent concern with fuel conservation has resulted in generally smaller air intakes whose shape and location are dictated primarily by low vehicle drag/high forward speed requirements. The new vehicle intake configurations make it more difficult to achieve adequate cooling under all conditions. They cause cooling flow velocity profiles to become distorted and underhood temperatures to be excessively high. Such problems make it necessary to achieve much better accuracy in measuring cooling flows.As the following descriptions show, each company or institution concerned with this problem has invested a lot of time and as a result gained considerable experience in developing measuring techniques that appear to achieve reliable results. There is, however, little uniformity at the present time among the methods used by different companies and no indication at this time of a trend towards a simple and universally acceptable measuring technique.

Road Vehicle Aerodynamics Forum Committee

Multi-Physics Modeling and Optimization Towards a Digital Twin of Quenching Process of Large-Scale Metallic Structures

F-0080-2024-1399

5/7/2024

Quenching is a heat treatment process for the rapid cooling of a metallic workpiece in water, oil, or air to obtain certain desired material properties. It is the most critical step in the sequence of heat-treating operations to preserve the solid solution formed at the solution heat-treating temperature by rapidly cooling to near room temperature. Because of the complex interaction between temperature, phase-transformation, and stress/strain relation that depends on the temperature distribution and the microstructure of the workpiece, there is no performance-informed quenching process that can be applied reliably to reduce the high scrap rate of airframe aluminum forging parts with a significant amount of residual stress and distortion. Since large aluminum forging parts are increasingly used in aerospace structures to enable structural unitization, it is important to construct a digital twin modeling approach to mirror the physical quenching process for minimizing scrap rate, increasing production efficiency, and engineers and machine operators' handling of variances in forging operations. A high-fidelity modeling of the coupling of thermal, metallurgical, and mechanical interactions is a key component to creating a digital twin of the physical quenching process. A high-fidelity thermal multi-phase computational fluid dynamics (CFD) model is applied to simulate fluid dynamics and temperature fields in the quenchant tank. The developed immersogeometric modeling approach is used next for an efficient model generation of a 3D workpiece with various dipping orientations. Given the temperature and pressure profiles predicted from the CFD-based heat transfer module, residual stress and distortion prediction modules are developed by including temperature and pressure fields mapping and temperature and strain rate dependent property evolution via Abaqus' user-defined subroutines. Verification and demonstration studies are performed using aluminum coupons dipped into a quenching tank with different orientations. Time histories of the temperature and residual stress fields were predicted to explore the relationship between the process and performance.

Lua, Jim, Phan, Nam, Piccoli, Joshua, Yan, Jinhui, Karuppiah, Anand, Shrestha, Kalyan

5 Ws of the Wearable Cooling and Heating Patch

TBMG-349228/1/2019

The patch — which serves as a personal thermostat — provides personalized cooling and heating at home, work, or on the go by cooling or warming the user's skin to a comfortable temperature and keeping it there as the ambient temperature changes.

Manufacturing of Transmission Quill Gear by Sinter Hardening

2019-26-01651/9/2019

Transmission quill gears are hot forged steel parts often used in constant mesh manual transmissions. The quill gear, which helps to transmit the power from input drive shaft to output shaft through driving gears. It’s having external teeth which is positively engaged with driving gear and sleeve. During gear selection sleeve take load from input shaft and transmit to driven gear. Quill gear directly engaged with driving gears on outer surface and bearing in inner surface which needs to have high strength and durability. These properties can be improved by carburization heat treatment in existing design such processes can lead to increased costs. We have developed quill gear through powder metallurgical process and then cooled rapidly in the furnace to get high strength and wear properties. Material composition are optimized to suit for sinter hardening process conditions. Thus, we have succeeded in the development of quill gears via sinter hardening, thus eliminating the forging and second hardening process. This paper will have detailed discussion on material chemical composition, sinter hardening process, mechanical and metallurgical properties comparison and validation results.

Gunalan, Magendran, Deshmukh, Rahul, Bane, Uttam

Compression Molding Press

TBMG-3336312/1/2018

Beckwood Press Company Fenton, MO 636-343-4100

HVAC System Bench Test Analysis for TXV Tuning

2018-01-0070

4/3/2018

In today’s automotive industry, the A/C (Air-conditioning) system is emerging into a high level of technological growth to provide quick cooling, warm up and maintaining the air quality of the cabin during all-weather conditions. In HVAC system, TXV plays vital role by separating high side to low side of vapor compression refrigeration system. It also regulates the amount of refrigerant flow to the evaporator based on A/C system load. The HVAC system bench laboratory conducts the test at different system load conditions to evaluate the outputs from tests during initial development stage to select the right TXV in terms of capacity and Superheat set point for a given system. This process is critical in HVAC developmental activity, since mule cars will be equipped with selected TXV for initial assessment of the system performance. The TXV tuning is conducted in system bench lab using defined test load cases which is developed using combination of given input boundary conditions and tests were conducted based on that. In this paper, major focus is laid on understanding potential importance of each system parameter, identify bench test boundary conditions that are critical for TXV set point decision making and understand internal stakeholder’s requirement. The whole process started with conducting personal interviews with internal stakeholders and suppliers to collect raw voices of customers. The DFSS tools were used to capture internal customer voices and translate into technical measures to provide insight of the data required for TXV selection. Tools used such as voice affinity, HOQ, Pugh Matrix, and Function tree diagram etc. The raw voices from interviews are translated into most important voice and mapped with current process using HOQ approach. The main purpose of house of quality is to derive the measurable targets to meet customer requirement. This study helps us to reduce the number of physical testing by approx. 35% without affecting TXV selection process and use objective approach to study system parameters.

Sambandan, Saravanan, Valencia, Manuel, Khawaja, Aamir, S, Sathish Kumar

Optimization of the Engine Intake Air Temperature through the Air Conditioning Unit

2018-01-09734/3/2018

In modern turbocharged internal combustion engines the cooling of the air after the compression stage is the standard technique to reduce temperature of the engine intake air aimed at improving cylinder filling (volumetric efficiency) and, therefore, overall global efficiency. At present, standard values for the intake air temperature are in the range 30-70°C, dependently on engine load, external air conditions and vehicle speed and the adoption of a dedicated cooling fluid operating at low temperatures (-10-0°C) is addressed as the most viable option to achieve an effective temperature reduction. This paper investigates a pilot engine set-up, featuring an evaporator on the intake line of a turbocharged diesel engine, tested on a high speed dynamometer bench: the evaporator was a part of an air refrigeration unit – the same used for cabin cooling - composed also by a compressor, a condenser and a thermostatic expansion valve. The effects of the undercooling of the charge air have been experimentally assessed in terms of fuel consumption and regulated emission reduction, evaluated on the most common engine operating points. Mechanical power needed by the compressor was obviously taken into account in order to assess the overall benefits. A fuel consumption reduction has been demonstrated in the order of 2.5% when the intake air subcooling is turned on. A benefit on the regulated emissions has been observed (NOx, PM). HC and CO behavior, on the contrary, deserves some more attention and involves engine control parameters (for instance, EGR rate) and combustion performances.

Di Battista, Davide, Vittorini, Diego, Di Bartolomeo, Marco, Cipollone, Roberto

Magnetic Cooling of Nanoelectronic Chips

TBMG-285643/1/2018

High-tech refrigerators have been used to reach temperatures as close to absolute zero as possible — 0 kelvin or -273.15 °C. Physicists aim to cool equipment to as close to absolute zero as possible, because these extremely low temperatures offer the ideal conditions for quantum experiments, and allow entirely new physical phenomena to be examined.

AVIONICS REFRIGERATION COOLING SYSTEM

ARINC728 (Current)10/27/2017

This standard provides standards for the in accordance with which aircraft operators and manufacturers can order avionics refrigeration units and can design installations for an ARCS.

Airlines Electronic Engineering Committee

Improved Modeling of Near-Wall Heat Transport for Cooling of Electric and Hybrid Powertrain Components by High Prandtl Number Flow

2017-01-06213/28/2017

Reynolds-averaged Navier-Stokes (RANS) computations of heat transfer involving wall bounded flows at elevated Prandtl numbers typically suffer from a lack of accuracy and/or increased mesh dependency. This can be often attributed to an improper near-wall turbulence modeling and the deficiency of the wall heat transfer models (based on the so called P-functions) that do not properly account for the variation of the turbulent Prandtl number in the wall proximity (y+< 5). As the conductive sub-layer gets significantly thinner than the viscous velocity sub-layer (for Pr >1), treatment of the thermal buffer layer gains importance as well. Various hybrid strategies utilize blending functions dependent on the molecular Prandtl number, which do not necessarily provide a smooth transition from the viscous/conductive sub-layer to the logarithmic region. This work relies on the k-ζ-f turbulence model and the underlying hybrid wall treatment, which is capable of predicting the near-wall momentum and heat transfer with more fidelity, compared to the standard or low-Re variants of the k-z-ε turbulence model. Based on a new DNS database for turbulent flow and heat transfer in a heated pipe (Reτ=360, Pr=1, 10, and 20), a two-layer wall heat transfer model has been formulated. A priori analysis and RANS predictions of the reference heated pipe flow are encouraging, showing improvements of the near-wall heat transfer predictions with respect to accuracy and mesh independence. The potential of the proposed model in real engineering applications is demonstrated in the cooling of electric/hybrid powertrain components, by simulating heat and fluid flow in the e-motor water jacket model.

Saric, Sanjin, Ennemoser, Andreas, Basara, Branislav, Petutschnig, Heinz, Irrenfried, Christoph, Steiner, Helfried, Brenn, Günter

Thermal Management of Power Batteries for Electric Vehicles Using Phase Change Materials: A Review

2016-01-12044/5/2016

As one of the most crucial components in electric vehicles, power batteries generate abundant heat during charging and discharging processes. Thermal management system (TMS), which is designed to keep the battery cells within an optimum temperature range and to maintain an even temperature distribution from cell to cell, is vital for the high efficiency, long calendar life and reliable safety of these power batteries. With the desirable features of low system complexity, light weight, high energy efficiency and good battery thermal uniformity, thermal management using composite phase change materials (PCMs) has drawn great attention in the past fifteen years. In the hope of supplying helpful guidelines for the design of the PCM-based TMSs, this work begins with the summarization of the most commonly applied heat transfer enhancement methods (i.e., the use of thermally conductive particles, metal fin, expanded graphite matrix and metal foam) for PCMs by different researchers. Newly developed TMS configurations such as the multi-layer PCMs and sandwiched ones are also discussed in detail. In addition, the hybrid TMS combining PCM cooling with air or liquid cooling, and battery heating by these PCM-based TMSs under cold environment are also summarized. Based on the analysis of previous studies, several possible research topics on PCM cooling are finally proposed in the conclusion/summary part.

Pan, Dongchang, Xu, Sichuan, Lin, Chunjing, Chang, Guofeng

An Investigation of Deformation Effects on Phase Transformation in Hot Stamping Processes

2016-01-03614/5/2016

To reduce the fuel consumption as well as to improve the crash safety of vehicles, the usage of hot stamping parts is increasing dramatically in recent years. Aisin Takaoka has produced hot stamping parts since 2001 and has developed various technologies related to Hot Stamping. In an actual hot stamping process, parts with insufficient strength could be produced sometimes at a prototyping phase, even under the proper forming conditions. In order to understand these phenomena, in this paper, phase transformation in a boron steel 22MnB5 under various cooling rates were investigated and the effects of pre-strain conditions on the phase transformations were characterised. Uniaxial tensile specimens were stretched under isothermal conditions to different strain levels of 0-0.3, at strain rates of 0.1-5.0/s and deformation temperatures of 650-800°C. A dilatometer was used to measure the dimensional changes of the specimen to rationalize the phase transformation of the boron steel during rapid cooling after deformation. The results showed that the deformation at austenite phase causes the reduction in martensitic phase transformation. For a certain strain level, deformation applied at a lower temperature and a higher strain rate would result in less amount of martensitic phase transformation. In addition, the relations between hot stamping conditions and Vickers hardness, which are normally used as a daily quality check in the industry, are also presented in the paper.

Matsumoto, Takeki, Li, Nan, Shi, Xin, Lin, Jianguo

Wavelet-based Fouling Diagnosis of the Heat Exchanger in the Aircraft Environmental Control System

2015-01-25829/15/2015

The Environmental Control System (ECS) of an aircraft provides thermal and pressure control of the engine bleed air for comfort of the crew members and passengers onboard. For safe and reliable operation of the ECS under complex operating environments, it is critical to detect and diagnose performance degradations in the system during early phases of fault evolution. One of the critical components of the ECS is the heat exchanger, which ensures proper cooling of the engine bleed air. This paper presents a wavelet-based fouling diagnosis approach for the heat exchanger. The approach is composed of three main steps: i) Feature extraction from the sensor data, where the data is preprocessed using wavelets for improving the information content of the features for fouling classification, ii) Pattern classification, where a classification algorithm is trained from the faulty and nominal datasets, and iii) Classifier evaluation, where the trained classifier is evaluated to determine the Correct Classification Rate (CCR). The fouling diagnosis process is built and tested with the sensor data generated from an experimentally validated ECS model provided by our industry partner.

Silva, Andre, Najjar, Nayeff, Gupta, Shalabh, D'Orlando, Paul, Walthall, Rhonda

Femtosecond Laser Processing of Metal and Plastics

TBMG-22197

6/1/2015

While precise and fast, the down side to cutting with microsecond (ms) fiber lasers has been that the parts require a number of post-processing operations after they are cut, which add significantly to part cost, and can also damage mechanically delicate parts.