Browse Topic: Thermal testing
ABSTRACT The both CFD (Computational Fluid Dynamics) and thermal analyses are used to predict a vehicle system thermal performance during the design development. The vehicle wall temperatures and compartments temperatures under various climatic conditions are predicted in MuSES thermal analyses. The temperature and air flow distributions inside the vehicle compartment are predicted in Star CCM+ CFD analyses. Recently, GDLS, Thermal Analytics, and CD-adapco jointly developed a CFD thermal analysis panel. This panel can be used to apply all boundary conditions to MuSES model and StarCCM+ CFD model by a few button clicks. It can map convection coefficients predicted in CFD analysis to the MuSES model boundaries; and vise versa, map wall temperatures and heat rates predicted in MuSES models to the boundaries in StarCCM+ models. Using this panel, the MuSES analysis and StarCCM+ analysis can be coupled to predict vehicle thermal performance with higher accuracy. Besides, most model inputs
Editorial Note: With the growth in adoption of addititively manufactured materials across aerospace and defense manufacturing, we decided to include two parts of this Air Force Research Lab report. Air Force Research Laboratory, Wright-Patterson Air Force Base, OH Universal test frames are generally either screw-driven or servohydraulic, which are both perfectly suited for uniaxial tensile testing experiments. A uniaxial test frame is comprised of several basic fixture components: loading device, a load cell, and a specimen gripping apparatus. An example of a commercially available tensile testing frame is shown below. Load cells are available in a wide range of load limits to accommodate the sensitivity needs for a wide range of materials and specimen geometries. ASTM E74 outlines the calibration procedure for load cells and must be followed to ensure proper measurement during testing, regardless of specimen size. Further details about alignment and gripping will be provided given
This test method provides performance data on candidate insulation systems as a function of time and temperature. These data give engineering information on the wire insulation candidate relative to the performance of materials already in use with a backlog of experience. These tests expose candidate insulation systems to a wide range of temperatures for short and long periods of time, while measuring the degradation of its physical properties. For aerospace use, end-point proof tests include mandrel bend, water soak, and dielectric integrity
This method is intended to define the continuous upper temperature limit (CUTL) of thermoplastic elastomers and thermoset rubber with durometer hardness <=90 Shore A, to oxidation or other degradation when exposed solely to hot air for an extended period of time
This SAE Aerospace Recommended Practice (ARP) contains guidance to assist users by providing a method to install an AS6224/2 repair sleeve
The validation of brake discs has remained, to this day, heavily reliant on “Thermal Abuse” or “Thermal Cracking” type testing, with many procedures so dated that most engineers active in the industry today cannot even recall the origin of the test. These procedures - of which there are many variants - all share the trait of greatly accelerating durability testing by performing repeated high power (high speed and high deceleration) brake applies to drive huge temperature gradients and internal stress, and often allowing the disc to get very hot, to where the strength of the material from which the disc is constructed is significantly degraded. There is little debate about whether these procedures work; by and large disc durability issues in the field are extremely rare. However, without the connection to the duty cycle in the field, it is extremely difficult to interpret results (especially since many standards allow significant cracking before a failure is declared), and this can lead
This SAE Recommended Practice establishes uniform test procedures and performance requirements for engine-off heating, ventilation, and air conditioning (HVAC) systems in order to achieve driver thermal comfort in both winter and summer rest periods. This specification will apply to heavy trucks with and without sleeper compartments, including but is not limited to Class 6, 7, and 8 powered vehicles
This SAE Recommended Practice establishes a uniform test procedures for on highway trucks equipped with an air-conditioning system used to condition the air in the cabin and sleeper compartment of the vehicle. This specification will apply to heavy trucks with and without sleeper compartments
This SAE Recommended Practice provides general design performance requirements and related test procedures for LED “white” lighting unit assemblies, other than signal and marking devices, used on Earthmoving, Road Building, and Maintenance off-road work machines as defined in SAE J1116. This report is intended to serve as a guide to standard practice and is subject to change to reflect additional experience and technical advances
The hot corrosion studies for the die-casted magnesium (Mg) silver (Ag) alloys are carried out through the steam heating route. The Magnesium Silver (QE22A) alloy is fixed under the top lid of the pressure cooker (2 liters) and filled with water and 5% salt (NaCl) solution. The specimens are treated with different time intervals (10, 20, and 30 minutes), with the steam temperature maintained at 100°C around the specimen. The results showed an increase in the corrosion rate with the increase in the steaming time. Further, after the specimens have cooled down to room temperature, similar experiments are repeated for the second and third cycles. Here the formation of the oxide layers over the specimen has reduced the corrosion rate. The structural, surface study was carried out through scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive spectroscopy (EDS) to know the corrosion behavior on the specimen. From the microstructure, it is noticed that the average
Thermoelastic instabilities in the contact of brake friction material cause hotbands and hotspots on the surface of brake disc. These phenomena generate thermal stresses that result in generation of cracks, which limit the lifetime of the discs. In the present work, the influence of the chemical composition of brake discs on the thermoelastic behavior of the system and on the lifetime of the discs was investigated. The experimental evaluation was carried out in an inertial dynamometer using the SAE J3080 standard procedure applied on a brake system. Two discs (namely A and B) with different chemical compositions were subjected to the tests. The brake pad composition was kept fixed. The thermoelastic effects on the inner surface of the disc were observed by contact (thermocouple) and noncontact measurement techniques (thermography), as well as through photographic images of the disc’s surfaces. Disc A showed negligible amount of Nb while disc B exhibited 0.360%. Besides, disc B
Internal combustion engines are the primary transportation mover for today society and they will likely continue to be for decades to come. Hybridization is the most common solution to reduce the petrol-fuels consumption and to respect the new raw emission limits. The gasoline engines designed for running together with an electric motor need to have a very high thermal efficiency because they must work at high loads, where engine thermal efficiency is close to the maximum one. Therefore, the technical solutions bringing to thermal efficiency enhancement were adopted on HVs (Hybrid Vehicles) prior to conventional vehicles. In these days, these solutions are going to be adopted on conventional vehicles too. The purpose of this work was to trace development guidelines useful for engine designers, based on the target power and focused on the maximization of the engine thermal efficiency, following the engine rightsizing concept. The originality of the present work stands in the comparison
This SAE Aerospace Standard (AS) establishes the aerodynamic flow-off requirements and test procedures for AMS1424 Type I and AMS1428 Type II, III, and IV fluids used to deice and/or anti-ice aircraft. The objective of this standard is to ensure acceptable aerodynamic characteristics of the deicing/anti-icing fluids as they flow off of aircraft lifting and control surfaces during the takeoff ground acceleration and climb. Aerodynamic acceptance of an aircraft ground deicing/anti-icing fluid is based upon the fluid’s boundary layer displacement thickness (BLDT) on a flat plate, measured after experiencing the free stream velocity time history of a representative aircraft takeoff. Acceptability of the fluid is determined by comparing BLDT measurements of the candidate fluid with a datum established from the values of a reference fluid BLDT and the BLDT over the dry (clean) test plate. Testing is carried out in the temperature range at which the fluid, undiluted and diluted, is to be used
This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This document provides standardized laboratory tests, test methods and equipment, and requirements for lighting devices covered by SAE Recommended Practices and Standards. It is intended for devices used on vehicles less than 2032 mm in width. Tests for vehicles larger than 2032 mm in overall width are covered in SAE J2139. Device specific tests and requirements can be found in applicable SAE technical reports
Nowadays, due to the internal combustion engine (ICE) industry’s orientation toward downsizing, modern efficient cooling systems with lower power consumption, small size, and high compactness are essential. To improve these items, applying precision cooling and boiling phenomenon are inevitable. Having an appropriate coolant flow velocity that leads to utilize only the advantages of boiling heat transfer has always been a challenge. Two experimental test rigs, one for modeling and accurate prediction of subcooled flow boiling and the other for measurement and validation of coolant velocity in a water jacket by particle image velocimetry (PIV) method, are set up. An accurate and robust empirical correlation for modeling of subcooled flow boiling that occurs in the water jacket is developed. Then, through a three-dimensional (3D) thermal analysis, the heat transfer parameters such as heat flux and temperature distribution of the ICE cylinder block and head are obtained numerically
Over the last decade, the electric vehicle (EV) has significantly changed the car industry globally, driven by Li-ion battery technology's fast development. However, the fire risk and hazard associated with this type of high-energy battery has become a significant safety concern for EVs. This report focuses on the thermal safety of lithium ion battery (LIB) with different lithium plating morphology. The orthogonal experimental design method is used to control the LIBs cycle and lithium plating condition. The L34 table was designed for cycling the LIBs, considering temperature, cut-off voltage, charging rate and pressure. The safety was evaluated by accelerating rate calorimetry (ARC). The self-heating onset temperature (Tsh) and thermal runaway onset temperature (Ttr) comparison between new cells and lithium plating cells show a significant deterioration. For LIB with different lithium plating morphology, including mossy and dendrite, the time duration from Tsh to Ttr presents a
This SAE Recommended Practice is applicable to all liquid-to-air, liquid-to-liquid, air-to-liquid, and air-to-air heat exchangers used in vehicle and industrial cooling systems
The fabrication or repairing of aircraft components made of Hastelloy X to be resolved using an arc welding technique. In this study, Hastelloy X was joint with ERNiCrCoMo-1 filler by pulsed current gas tungsten arc (PCGTA) welding. The high temperature tensile property of the weldment has been evaluated at three different temperatures such as 700 °C, 800 °C and 900 °C. The tensile properties such as yield strength (294, 259 and 205 MPa), ultimate tensile strength (475, 396 and 245 MPa) and percentage of elongation or ductility (17, 14 and 11 %) follows the similar trend with temperature at 700 °C, 800 °C and 900 °C respectively. It revealed the values of all the properties are decreased as the temperature increased. The lowest strength was evaluated for weldment at 900 °C. The high temperature tensile test also revealed that the fracture of weldments for all three conditions is found at the weld centre (WC). Even though, the failure happened at WC, the high temperature tensile
This SAE Aerospace Standard (AS) provides minimum performance and design standards for a handheld, high-intensity, flashing Aviation Visual Distress Signal (AVDS) based on light-emitting-diode (LED) technology operating simultaneously in visible (white) and near infrared (NIR) spectra designed to facilitate location and rescue of aviation accident/ditching survivors in open sea conditions
This SAE Aerospace Standard (AS) establishes the aerodynamic flow-off requirements and test procedures for AMS1424 Type I and AMS1428 Type II, III, and IV fluids used to deice and/or anti-ice aircraft. The objective of this standard is to ensure acceptable aerodynamic characteristics of the deicing/anti-icing fluids as they flow off of aircraft lifting and control surfaces during the takeoff ground acceleration and climb. Aerodynamic acceptance of an aircraft ground deicing/anti-icing fluid is based upon the fluid’s boundary layer displacement thickness (BLDT) on a flat plate, measured after experiencing the free stream velocity time history of a representative aircraft takeoff. Acceptability of the fluid is determined by comparing BLDT measurements of the candidate fluid with a datum established from the values of a reference fluid BLDT and the BLDT over the dry (clean) test plate. Testing is carried out in the temperature range at which the fluid, undiluted and diluted, is to be used
This specification covers pyrometric requirements for equipment used for the thermal processing of metallic materials. Specifically, it covers temperature sensors, instrumentation, thermal processing equipment, correction factors and instrument offsets, system accuracy tests, and temperature uniformity surveys. These are necessary to ensure that parts or raw materials are heat treated in accordance with the applicable specification(s
This specification covers the following types and classes of extinguishers: Type I Stored pressure type Category A - Operational Temperature range −40 to +140 °F (−40 to +60 °C) Category B - Operational Temperature range +35 to +140 °F (+1.7 to +60 °C) Type II Cartridge operated type Category A - Operational Temperature range −40 to +140 °F (−40 to +60 °C) Category B - Operational Temperature range +35 to +140 °F (+1.7 to +60 °C
This SAE Recommended Practice is applicable to all heat exchangers used in vehicle and industrial cooling systems. This document outlines the tests to determine the heat transfer and pressure drop performance under specified conditions. This document has been reviewed and revised by adding several clarifying statements to Section 4
For the gasoline engine, the isochoric process is the ideal limit of the ideal processes. During the project, a combustion engine with real isochoric boundary conditions is built. A “resting time” of the piston for several degrees crank angle in the top dead center (TDC) can be realized with a special crank drive. This crank drive consists of two crankshafts with different strokes, which are combined. The two crankshafts rotate with a ratio of two to one in opposite directions. The total stroke corresponds to the amount of the first crankshaft, so it is possible to investigate different strokes of the second crankshaft in the same crankcase. Different “resting times” can be achieved by different strokes of the second crankshaft. A specific combination of both crankshafts make a stroke possible which corresponds to that of a conventional combustion engine. In addition to the standard cylinder pressure sensor, a quick surface temperature probe is also used as supplementary measurement
This test method is applicable for rating various materials, such as automotive trim materials and insulation composites, for their ability to resist heat transfer, heat degradation, odor, smoking, and exothermic reaction under prescribed temperature
Lean burn is one method for improving thermal efficiency in spark ignition (SI) engines. Suppression of knocking provides higher thermal efficiency, and ethanol blending is considered an effective way to suppress knocking due to its high octane and high latent heat of evaporation. We investigate the effect of ethanol blending on knocking in an SI engine under lean operating conditions. The Livengood-Wu (LW) integral was performed based on ignition delay duration estimated from a zero-dimensional detailed chemical reaction calculation with pressure and temperature histories. Knocking was suppressed and thermal efficiency increased with ethanol-gasoline blending fuel, even at 0.5 equivalence ratio. Decrease in unburned gas temperature by latent heat of evaporation had a comparable influence on knocking suppression, which was supported by LW integral analysis
Current approaches to heat rejection prediction during the development stage of a new engine are mostly based on maps built upon experimental data. However, these maps can be obtained fairly late in the development process, when at least a prototype of the engine can be run on the test bench. Furthermore, such experimental maps are limited to a discrete number of points measured at fixed operating conditions. An innovative approach based on 1D simulation was tested in the commercial 1D multi-physics code GT-SUITE, developed by Gamma Technologies LLC, to advance the moment at which reliable heat rejection calculations can be effectively used to support the engine and cooling system design. A fully physical Diesel engine performance model - featuring a predictive combustion model - was integrated with a detailed finite element wall temperature solver based on the 3D meshing feature available in GT-SUITE. Coolant and oil hydraulic circuits were implemented in the model and used to predict
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