Thermal Engineering Overview

Confused? You're not alone. This is a puzzle encountered by people who want to ensure their computer investment is protected with the right products to keep it functioning for years to come. The present problem with cooling microprocessors is a relatively new issue -- about 4 years old. It stems from the collision of two conflicting trends -- end-user desire for more powerful microprocessors to run the next generation software, and the equally strong demand for smaller, more mobile computer form factors. With each, the introduction of faster next-generation semiconductors aimed at improving computing power, heat concentration problems increase. Thermal energy generated within these devices can be compared to that of a stovetop burner. Today's generation of Pentium, Athlon, and Power PC chips can dissipate more than 100 watts of power. In straight forward terms, you could fry an egg on top of any of these chips. Choosing the right cooling solution is a complex task requiring the coordination of several factors and requires good thermal engineering. So how is it that certain upgrade processors do not require a heat sink with a miniature fan solution? To answer that question, we need to first understand the fundamental problem. Heat to be removed must travel from the microelectronic chip to the surrounding air stream. As heat flows, it encounters a series of thermal resistance that impedes overall heat removal. The laws of physics dictate that performance and reliability of semiconductor and integrated circuit devices are absolutely constrained by temperature. Mathematicians have worked out formulas that inform us for every 10°C rise of the junction temperature (this corresponds to any one of the 4 million transistors that may be on a microprocessor) the failure rate doubles. There are any number of ways device temperature related failures modes may be manifested on the electronic level that cannot be visually detected. These failure modes include such items as gate dielectric strength, junction fatigue, electromigration diffusion, electrical parameter shifts, and thermal runaway any of which could ultimately result in a failed CPU. But what does all of this tech-jargon really mean to you and me? It means that computer manufacturers and suppliers of upgrade processors must work diligently to ensure that their products are engineered properly to provide sufficient cooling to the microprocessor for an extended length of time. Thermal engineering is more than a way of controlling heat and temperature rise in a computer. By definition, thermal engineering requires designers to pay attention to every aspect of heat generation and removal in an electronics system. It is NOT putting the biggest heat sink or biggest fan on a semiconductor. Rather, it is the careful and purposeful selection of parts and components, with heat removal in mind. An ideal cooling design achieves the desired junction temperatures, is compact in size, low in cost, adaptable enough to fit into system designs. Attempts to increase capacity by using larger heat sinks, higher air velocities and fan heat sink combinations will be wrought with diminishing returns. Contrary to market demands for smaller packaging and higher performance, these solutins add to the packaging volume with larger parts or decreasing the system reliability. So how do we choose the best solutions? In early stages of system design as well as the package design for the processor, thermal issues need to be recognized and advanced engineering solutions brought to the design table. The design of upgrade processors allows thermally optimized packages to be utilized in non-optimized systems. This is due to upfront thermal engineering efforts where materials, manufacturing techniques, and thermal barriers all maximize a processor's performance and reliability at the lowest cost and smallest sizes. While these upgrade processors then offer advanced thermal solutions where they can replace less reliable fan/sink combinations, they represent a change to thermal engineering in the earliest stages of product design. Why don't the system manufacturers implement these advanced solutions in the original product design cycle? Often this is due to the fast pace product development cycles, and often it is just because the solutions were not available at the time the system was ready for market. Will you likely see lower reliability solutions in future system designs? Not if thermal engineering takes place!

COMBUSTION IN SPARK-IGNITION ENGINES

COMBUSTION IN SPARK-IGNITION ENGINES
In a conventional spark-ignition engine, the fuel and air are homogeneously mixed
together in the intake system, inducted through the intake valve into the cylinder where it mixes
with residual gases and is then compressed. Under normal operating conditions, combustion is
initiated towards the end of the compression stroke at the spark plug by an electric discharge. A
turbulent flame develops following the ignition and propagates through this premixed charge of
fuel and air, and also the residual gas in the clearance volume until it reaches the combustion
chamber walls. Combustion in the SI engine may be broadly divided into two general types, viz.,
normal combustion and abnormal combustion.
STAGES OF COMBUSTION IN SI ENGINES
A typical theoretical pressure-crank angle diagram, during the process of compression
(a→b), combustion (b→c) and expansion (c→d) in an ideal four-stroke spark-ignition engine is
shown in Fig.1. In an ideal engine, as can be seen from the diagram, the entire pressure rised
uring combustion takes place at constant volume i.e., at TDC. However, in an actual engine this
does not happen. The detailed process of combustion in an actual SI engine is described below.
The combustion process in an SI engine consists of three stages.

The pressure variation due to combustion in a practical engine is shown in Fig. 2. In this
figure, A is the point of passage of spark (say 20°bTDC), B is the point at which the beginning of
pressure rise can be detected (say 8° bTDC) and C the attainment of peak pressure. Thus AB
represents the first stage and BC the second stage and CD the third stage.

Thermal Engineering is an established

Thermal Engineering is an established, privately owned and globally-oriented supplier of specialised components and assemblies to the aerospace industry. We provide a responsive, focused service backed by many years of experience and a wide range of knowledge of the industry's requirements and standards. Above all, we offer practical, comprehensive and cost-effective solutions to airframe and engine manufacturers, system integrators and other 1st tier suppliers.

Thermal engineering are specialists in :-

• Hot forming and cold forming (hard aerospace alloys)
• Sheet metal components, assemblies and fabrication
• Thermal insulation and protection

Thermal Engineering Overview

Thermal Engineering Overview

Imagine you have just finished making the last few changes to a presentation for one of your biggest clients, the most critical presentation of the year. Then, your worst fear comes true - your system suddenly fails. Data stored on your hard drive is lost. You pull the cover off the machine and you see that the miniature fan on top of the CPU has stopped running. You quickly realize that your microprocessor failed due to inadequate cooling. Promptly, you purchase an upgrade microprocessor and behold - it has a heat sink with no fan!Confused? You're not alone. This is a puzzle encountered by people who want to ensure their computer investment is protected with the right products to keep it functioning for years to come. The present problem with cooling microprocessors is a relatively new issue -- about 4 years old. It stems from the collision of two conflicting trends -- end-user desire for more powerful microprocessors to run the next generation software, and the equally strong demand for smaller, more mobile computer form factors. With each, the introduction of faster next-generation semiconductors aimed at improving computing power, heat concentration problems increase. Thermal energy generated within these devices can be compared to that of a stovetop burner. Today's generation of Pentium, Athlon, and Power PC chips can dissipate more than 100 watts of power. In straight forward terms, you could fry an egg on top of any of these chips. Choosing the right cooling solution is a complex task requiring the coordination of several factors and requires good thermal engineering. So how is it that certain upgrade processors do not require a heat sink with a miniature fan solution? To answer that question, we need to first understand the fundamental problem. Heat to be removed must travel from the microelectronic chip to the surrounding air stream. As heat flows, it encounters a series of thermal resistance that impedes overall heat removal. The laws of physics dictate that performance and reliability of semiconductor and integrated circuit devices are absolutely constrained by temperature. Mathematicians have worked out formulas that inform us for every 10°C rise of the junction temperature (this corresponds to any one of the 4 million transistors that may be on a microprocessor) the failure rate doubles. There are any number of ways device temperature related failures modes may be manifested on the electronic level that cannot be visually detected. These failure modes include such items as gate dielectric strength, junction fatigue, electromigration diffusion, electrical parameter shifts, and thermal runaway any of which could ultimately result in a failed CPU. But what does all of this tech-jargon really mean to you and me? It means that computer manufacturers and suppliers of upgrade processors must work diligently to ensure that their products are engineered properly to provide sufficient cooling to the microprocessor for an extended length of time. Thermal engineering is more than a way of controlling heat and temperature rise in a computer. By definition, thermal engineering requires designers to pay attention to every aspect of heat generation and removal in an electronics system. It is NOT putting the biggest heat sink or biggest fan on a semiconductor. Rather, it is the careful and purposeful selection of parts and components, with heat removal in mind. An ideal cooling design achieves the desired junction temperatures, is compact in size, low in cost, adaptable enough to fit into system designs. Attempts to increase capacity by using larger heat sinks, higher air velocities and fan heat sink combinations will be wrought with diminishing returns. Contrary to market demands for smaller packaging and higher performance, these solutins add to the packaging volume with larger parts or decreasing the system reliability. So how do we choose the best solutions? In early stages of system design as well as the package design for the processor, thermal issues need to be recognized and advanced engineering solutions brought to the design table. The design of upgrade processors allows thermally optimized packages to be utilized in non-optimized systems. This is due to upfront thermal engineering efforts where materials, manufacturing techniques, and thermal barriers all maximize a processor's performance and reliability at the lowest cost and smallest sizes. While these upgrade processors then offer advanced thermal solutions where they can replace less reliable fan/sink combinations, they represent a change to thermal engineering in the earliest stages of product design. Why don't the system manufacturers implement these advanced solutions in the original product design cycle? Often this is due to the fast pace product development cycles, and often it is just because the solutions were not available at the time the system was ready for market. Will you likely see lower reliability solutions in future system designs? Not if thermal engineering takes place!

COMPRESSER TERMAL REPIRE KIT

FIELD SERVICE AND CONSULTING

FIELD SERVICE AND CONSULTING

The SEA problem solving arsenal includes dozens of weld overlay strategies, thermal spray coatings which address a complete spectrum of wear, corrosion, oxidation and friction control issues, heat treatments and diffusion coatings, thin film processes such as PVD and CVD, composite bearing and wear control systems, and PIM and HIP design based surface modifications.

Oxy-Fuel Thermal Spray

Some of these treatments are patented, some are proprietary, and some are in the public sector. The uniqueness of the SEA approach is that it doesn't matter where the answer comes from as long as it provides the productivity improvement required by the customer.

Before even the best coating/treatment can be applied to a mechanical system, something must be known about what is wrong with the system, what degrading influences are present, and what decay modes are at work.

So the SEA failure analysis capability is an important preface to the application of the surface modification techniques which we have available.

VEHICLE THERMAL MANAGEMENT

EV Battery Cooling/Heating System (Coolant to Refrigerant/Air)

• Development of the entire vehicle thermal management
• Related supply chain management