Mechanical and Thermal Design: Overview, Process, and Standards
What is mechanical and thermal design?
Mechanical and thermal design is the engineering division that leverages thermodynamics to design technologies and products. Thermal design is the application of thermodynamics to design real-world applications, while mechanical design involves designing the structural and dynamic loading for smallsat hardware. It also includes designing the PCB layout, the size of the PCB, the housings, and the structures, all of which are subject to the thermal dissipation of electronics and the dynamic thermal radiation environment on-orbit. Thermal design is essential when striving for fanless specifications, as the design engineers must reduce heat generation and devise measures to increase heat dissipation. This requires communication between engineers and mutual understanding of the thermal design process. Thermal design is often used for electronic component cooling, such as CPU cooling, microprocessor cooling and GPU cooling.
What are the steps in mechanical and thermal design process?
Step 1: Defining thermal boundary conductance
Thermal boundary conductance is an important part of the mechanical and thermal design process. It is a measure of the effectiveness of an interface between two solid surfaces to transmit heat. It is calculated by applying a conservation of energy approach, which involves discretising motor components into small elements and applying an energy balance on each element.
The thermal boundary conductance coefficient (k’) is used to calculate the interface thermal resistance (R link ) across a boundary with an area A. The thermal boundary conductance coefficient (k’) is a product of the thickness (t) and thermal conductivity (k) of any interface material present. If no interface material is present, average values of k’ can be used based on empirical data published in the literature.
To calculate thermal boundary conductance, the individual thermal conductances of each component (e.g. stator) need to be added together to obtain the overall thermal conductance network. The thermal conductance network of each component is developed independently, and the interface thermal conductance network is then built up based on the interface conditions. The elements at the boundary of the components should be treated with the appropriate boundary conditions such as prescribing a heat transfer coefficient if it is exposed to air.
For example, if a motor component has four elements, the thermal conductance matrix [K] can be formulated as shown in equation (4).
The diagonal elements of the thermal conductance matrix represent the quantitative sum of the thermal conductance of all the paths connected to the i th element, while the off-diagonal elements represent the thermal conductance of the path between the i th and i th element as represented by the row and column of the matrix respectively.
Once the thermal conductance network has been established, the thermal resistance of the interface can be calculated using equation (7). At boundaries which have multiple layers of material, the thermal resistances are added in series.
Step 2: Model development
Modeling is an essential part of the mechanical and thermal design process as it allows engineers to develop models that can provide insights into the quality and performance of the product in the early stages of development. Modeling also enables engineers to make predictions about the resources needed to implement the design and validate complex system behavior. This can help engineers identify potential issues with the design, such as excessive heat dissipation, and plan solutions such as the selection of appropriate heat sinks that can increase the wetted area for heat transfer. Ultimately, modeling aids in the mechanical and thermal design process by providing a way to assess the design and make informed decisions to ensure an optimal outcome.
Step 3: Calculation of thermal risk
The calculation of thermal risk in the mechanical and thermal design process involves a few key steps. First, it is necessary to define the boundary conditions, such as the maximum power dissipation of the major chips, the power levels of the hard disk drives, power supplies, video cards, PCMCIA slots, and the ambient temperature. Ideally, the ambient temperature should be 35–40°C.
The second step is to do a thermal budgeting of the complete thermal solution, which requires the distribution of the total thermal resistance from junction to ambient among various sections of the thermal path, such as from chip-to-package, package-to-heat sink and heat sink-to-inside ambient, and inside-to-outside ambient. This should be done in coordination with the other considerations, such as costs, available technologies, reliability levels, and suppliers.
The third step is to select the appropriate coolant and cooling mode based on the thermal resistances. For example, for a wetted area of 10 cm2, the external thermal resistances range from 100°C W−1 for natural air convection, to 33°C W−1 for forced air convection, to 1°C W−1 for forced fluorochemical liquid convection. If direct cooling from the package surface is inadequate, heat sinks can be used to increase the thermal transfer area, which can reduce the external thermal resistances to under 15°C W−1 in natural convection and as low as 5°C W−1 for moderate forced convection.
Finally, the thermal system design details should be elaborated. This includes the selection of die-attach materials, package types, bonding techniques, via designs, etc., for the internal thermal management. For external thermal management, it involves the selections of the cooling modes, heat sinks, attachment processes, etc. Additionally, the physical properties of the die material, such as density, thermal conductivity, heat capacity, and emissivity, should be taken into account.
By following these steps, the thermal risk in the mechanical and thermal design process can be accurately calculated.
Step 4: Design of thermal management systems
Step 1: Define Boundary Conditions: The first step in the design process is to define the boundary conditions, such as the maximum power dissipation of the major chips, the power levels of the hard disk drives, power supplies, video cards, and PCMCIA slots, as well as ambient temperature. Generally, most designers use 35-40°C as the ambient temperature.
Step 2: Thermal Budgeting: The second step is to create a thermal budget for the entire thermal solution. This involves dividing the total thermal resistance from junction to ambient among various sections such as chip-to-package, package-to-heat sink and heat sink-to-inside ambient, and inside-to-outside ambient. Furthermore, the design must take into account other factors such as cost, available technologies, reliability levels, suppliers, and package manufacturing yields.
Step 3: Cooling Mode Selection: When selecting the cooling mode for the component, the convective thermal resistance must be considered. This process takes into account factors such as the wetted area, the type of coolant, and the type of cooling mode. For example, a 10 cm2 wetted area can range from 100°C W-1 for natural air convection, 33°C W-1 for forced air convection, and 1°C W-1 for forced fluorochemical liquid convection.
Step 4: Heat Sink Selection: If the direct cooling from the package surface is not sufficient, heat sinks can be used to increase the wetted area for heat transfer. Typical air-cooled heat sinks can reduce the external thermal resistance to under 15°C W-1 in natural convection and as low as 5°C W-1 for moderate forced convection. As for liquid cooled heat sinks, they can reduce the resistance to 1°C W-1 or lower.
Step 5: Final Design: Once the coolant and cooling mode have been determined, the thermal system must be designed in detail. This involves selecting die-attach materials, package types, bonding techniques, via designs, cooling modes, heat sinks, and attachment processes. It is important to coordinate these decisions with the overall cost, available technologies, reliability levels, suppliers, and package manufacturing yields.
Step 5: Implementing analytical methods
Step 1: Identify the engineering codes and regulations that apply to the mechanical and thermal design process. This includes codes such as ASME, API, ANSI, ASTM, AWS, MIL, IBC, ISO, AWWA, AAR, and international codes such as DIN and BSI.
Step 2: Perform engineering design and analysis while following the relevant codes and regulations. This may involve closed-form Design-By-Rule methods (ASME Section VIII Division 1) or finite element analysis and Design-By-Analysis (ASME Section VIII Division 2).
Step 3: Perform thermal design by using thermal software to work out all the details and ensure that the final product has the desired properties.
Step 4: Utilize analytical methods such as finite element analysis (FEA), thermal and transient analysis, heat transfer analysis, stress and seismic analysis, vibration and fatigue analysis and fracture mechanics analysis to maximize equipment reliability and control costs.
Step 5: Perform inspections and tests for air flow and temperature, mechanical tests, and environmental tests to ensure the product meets the requirements.
Step 6: Finalize the design and conduct a thorough review of the results.
Step 6: Calculation and analysis of temperature distribution in deck lid panels
In order to calculate and analyze the temperature distribution in deck lid panels, thermal modeling can be used. Firstly, it is necessary to define proper boundary conditions in order to assess thermal transport away from the panels. Then, a solver can be used to solve the control set point temperatures that will minimize the average panel surface temperature deviation.
Once the boundary conditions and control set points are established, a thermal simulation can be run to predict the temperature distribution on the surface of the panel. An example of this can be seen in Fig. 12.13, where the predicted temperature distribution on the surface of a tool in contact with the load bearing insulation system is shown. The locations of the load posts are apparent, and reflect the thermal losses associated with their presence.
The results from the thermal modeling can then be used to assess temperature uniformity. In the example shown in Fig. 12.14, with constant temperature set points a temperature variation of ~ 13 °C is obtained. However, with the optimized set point temperatures, as shown in Fig. 12.15, the average temperature is slightly higher (at 450 °C) but the temperature variation is only reduced slightly. It is important to note that the use of a limited number of linear heater rods placed below a complex surface geometry will limit the temperature uniformity that can be achieved. Additionally, radiative heat transfer between opposing tool halves can help to even out temperature gradients. Finally, it is important to take into account the influence of incoming preheated blanks on the steady-state tool surface temperature gradients.
Step 7: Implementing heat loss calculations
Step 1: Begin by calculating the overall heat exchanger design, including the thermal design, mechanical design and manufacturing considerations for the specific application.
Step 2: Select overall plate dimensions including length and width of the cross and counterflow sections and flow channel size.
Step 3: Calculate the fluid outlet temperatures for the specified or desired heat exchanger effectiveness.
Step 4: Obtain the mean temperature on the hot and cold sides, and evaluate the fluid bulk mean thermophysical properties, such as the viscosity, specific heat capacity, density, thermal conductivity and Prandtl number.
Step 5: Calculate the effectiveness (ε) and number of transfer units (NTU) of the heat exchanger.
Step 6: Determine the heat exchanger surface area using the fact that it is identical for the hot and cold sides, and the approximate relationship between the air- and gas-side heat transfer coefficients.
Step 7: Calculate the mass flux, Reynolds number, friction factor and Colburn factor for the air and gas side flows.
Step 8: Calculate the hot and cold side pressure drops in counterflow and cross-flow sections using the procedure outlined in, e.g., Kays and London (1984).
Step 9: Calculate the total relative pressure drop (Δp/p) total and check whether it meets the specified requirement. If the (Δp/p) total is not within the requirements, then return to the beginning and modify the plate dimensions.
Step 8: Managing thermal risk
Managing thermal risk can help with the mechanical and thermal design process by reducing the possibility of damage to components due to extreme temperatures. By properly defining the boundary conditions, such as maximum power dissipation of major chips, power levels of hard disk drives, power supplies, video cards, PCMCIA slots, and ambient temperature, and then budgeting the thermal solutions, the external thermal resistance can be reduced to lower levels to reduce the risk of damage due to high temperatures. For example, by using heat sinks, the external thermal resistance can be reduced to as low as 5°C W-1 for moderate forced convection and even lower for liquid cooled heat sinks. Furthermore, thermal modeling can be used to estimate the arrangement of cells and cooling measures before prototyping a BESS. By taking such measures, the risk of damage due to extreme temperatures is greatly reduced.
Standards on mechanical and thermal design processes
1. Cad tools
What are the CAD tools for mechanical and thermal design processes? [Expanded list]: Autodesk, Dassault Systemes, and Fusion 360 are the most popular CAD tools for mechanical and thermal design processes. Autodesk provides a suite of tools for mechanical design, documentation, product simulation and analysis, while Dassault Systemes is a powerful 3D CAD tool for mechanical design of components and assemblies with optional SolidWorks Simulation capabilities. Fusion 360 is a cloud-based 3D CAD tool that takes a different approach to system/assembly design. CATIA is exceptional at handling large, complex systems, and is good for modeling 3D objects in the context of its real-life behavior. For engineering graphics, codes and standards are available for producing quality drawings, such as dimensioning, projection, and exploded and assembly views. For custom thermal management solutions, the Thermal Wizard tool based on proven thermal calculations is used to find the right cooling solution. Additionally, Laird Thermal Systems’ Sourcing and Quality departments are engaged to find suppliers providing high-quality components at a low cost.
2. Specification of the final product
The final product must meet the following specifications:
- Electronic circuit design must be reliable and capable of delivering the desired performance.
- Mounting board (PCB) design must ensure the appropriate positioning and layout of components, as well as the correct size and shape of the PCB.
- Mechanical design must be able to produce housings, structures, and other components that are suitable for the application.
- Software design must produce software that is capable of operating effectively on the hardware.
- Thermal design must be able to reduce heat generation, increase heat dissipation, and be capable of achieving a fanless design.
- Products must adhere to the NASA standard for all spacecraft and meet the requirements for flight hardware specified in this document.
- Manufacturers must be authorized distributors with the necessary quantity of products.
- Design quality must be high, ensuring that prototypes are reliable and can be quickly mass produced with no problems in the marketplace.
3. Thermal analysis
Thermal analysis is a branch of engineering that leverages thermodynamics to design technologies and products. It is a critical process in both mechanical and thermal design as it allows engineers to accurately predict the effect of different welding parameters, heat generation mechanisms, convective contribution, and temperature-dependent heat sources on the design of a product. Thermal modelling also helps engineers to make informed decisions on the choice of material and numerical framework, as well as the mechanical and environmental tests that need to be conducted to meet specific requirements. By using thermal analysis, engineers can ensure that their designs are safe and efficient, and that the end product meets the given requirements.
4. Thermal design techniques
Thermal design techniques available for electronic components cooling include defining boundary conditions such as maximum power dissipation of major chips, power levels of hard disk drives, power supplies, video cards, and PCMCIA slots, and ambient temperature; thermal budgeting of the complete thermal solution; selection of die-attach materials, package types, bonding techniques, via designs, etc. for internal thermal management; selection of cooling modes, heat sinks, attachment processes, etc. for external thermal management; and the use of convective thermal resistances for direct contact with gas or liquid, or heat sinks.
5. Electronic systems engineering design
The electronic design process involves several steps to ensure a successful product design. Below are the steps in the process:
- Define the product specifications and objectives.
- Analyze the product requirements to determine the appropriate design parameters, such as power supply requirements, form factor, performance, etc.
- Use the Thermal Wizard tool to create a thermal management solution based on the product requirements.
- Work with suppliers to identify the best components to meet the requirements and help keep costs low.
- Develop a circuit diagram that meets the required specifications.
- Design the printed circuit board (PCB) layout using CAD software.
- Define mounting holes, connectors, and other components on the PCB.
- Design the mechanical structure and housing.
- Create the software code to use in the product.
- Test the product to ensure it meets all specifications.
- Analyze the thermal design of the product and make sure it meets the required design parameters.
- Finalize the design and prepare the product for manufacturing.
6. Tool design
Step 1: Conduct research on CAD tools to find the one that best suits your needs for mechanical and thermal design. Consider the features, capabilities, user-friendliness, and cost of available tools.
Step 2: Determine your design requirements and objectives. This should include what the tool should be able to do and any specific features or capabilities you need.
Step 3: Create detailed specifications for the design tool. This should include the functional and technical requirements, as well as any user interface and user experience requirements.
Step 4: Design the tool using a 3D CAD program, such as Dassault Systemes or Autodesk. This includes sketching out the design, building the model, and adding functionality and features.
Step 5: Test and validate the design. This involves setting up tests to ensure that the tool meets all project requirements and performs as expected.
Step 6: Implement the design. This includes deploying the design to production and any necessary post-deployment processes, such as updating user manuals or providing training to users.
7. Heat transfer coefficient
Heat transfer coefficient, also known as convective heat transfer coefficient, is a measure of the thermal performance of a material or device in an environment. It is used to quantify the amount of heat that is transferred between a solid surface and the surrounding environment. It is commonly used in mechanical and thermal design processes to determine the amount of heat that needs to be dissipated in order to maintain a desired temperature. The heat transfer coefficient is typically expressed in W/m2/K, and is calculated by dividing the thermal energy transferred between a material and its environment by the surface area and the temperature difference between the two.
8. Heat transfer matrix
The heat transfer matrix is a m x m matrix of thermal conductance and heat capacitance that is used to describe the thermal behaviour of a motor component. This matrix is derived by discretising the component’s components into small elements and applying an energy balance on each element. It takes into account the heat generated, stored, and net heat flow in or out of the element, as well as the conduction and convection thermal resistances between elements. The thermal conductance matrix [K] is derived based on the thermal conductivity and thickness of interface materials, or empirical data for boundaries exposed to air. The heat transfer matrix affects mechanical and thermal design processes, since it provides a quantitative description of how heat energy is transferred, distributed and dissipated in a motor component. This information can be used to develop thermal models to aid design decisions and optimise performance.
9. Heat transport equation
The heat transport equation is an equation that describes the transfer of heat energy across a solid material interface. The equation is important for mechanical and thermal design processes because it takes into account the frequency, polarization, and direction of phonons that are traveling through both materials, as well as the temperature difference between the two materials. With this equation, designers can accurately estimate the thermal boundary conductance, i.e. the conductance coefficient, which is defined as the thermal boundary conductance, h [W/m2 K]. This allows them to assess how much heat energy is being transferred across the interface and make the necessary design adjustments to ensure efficient heat transport while also accounting for any temperature drops.
10. Cadmium telluride cells
The process of manufacturing cadmium telluride cells begins with thermal modeling. This involves calculating the overall heat management in the battery energy storage system (BESS) using laboratory tests. This helps to determine the cell arrangement and cooling measures in the module before prototyping begins.
The next step is to monitor for overcharge and overheating. This is done using battery-management systems to ensure that the system does not exceed the nominal energy capacity of the cell or module. If too high upper voltage charging limits are used, the materials may not be able to store all of the electric energy and may become unsafe due to overheating. This is why it is important to use the correct cut-off voltages when charging the cells.
The best place for thermal sensing elements is directly at the cell connectors to ensure that the heat is dissipated properly. Additionally, the battery room must be specially ventilated if using a water-based electrolyte, such as lead-acid cells, redox-flow cells, nickel-cadmium, and nickel-metal-hydride cells. For lithium-ion BESS, special battery rooms are not mandatory, but it is still recommended to use the higher safety standard.
Finally, the cells must be cooled by air convection or forced convection by fans. If necessary, liquid cooling may also be used. All the process steps must be carefully followed to ensure the long lifetime and safety of cadmium telluride cells.
What is the purpose of mechanical and thermal design?
The purpose of mechanical and thermal design is to develop real-world applications for the science of thermodynamics and to create devices, products and systems that meet specific functional and interfacing requirements. Thermal design leverages thermodynamics to control the temperature of components, as well as to dissipate or absorb heat from or to other components or sources. Mechanical design also plays a part in ensuring that the device is able to withstand dynamic and static structural loads, as well as being able to function in hot and cold environments. Optimizing thermal design requires communication between engineers in order to create a unified product design, which can lead to reductions in both manpower and costs.
What processes and standards are used in mechanical and thermal design?
Mechanical and thermal design processes and standards include engineering analysis, simulations, materials testing, and quality control. Additionally, mechanical analysis such as finite element analysis (FEA) and thermal analysis such as computational fluid dynamics (CFD) are used to ensure the design meets requirements and standards. Design must also adhere to Military Standard 810 (MIL-STD-810) for rugged rack solutions and thermal solutions, with airflow and temperature tests, mechanical tests, and environmental tests to ensure the design is suitable for the intended environment.
What are the key elements of a thermal system?
A thermal system consists of four key elements: boundary conditions, thermal budgeting, internal thermal management, and external thermal management. Boundary conditions include the maximum power dissipation of major chips, power levels of hard disk drives, power supplies, video cards, PCMCIA slots, and ambient temperature. Thermal budgeting involves distributing total thermal resistance from junction to ambient among various sections of the thermal path. Internal thermal management considers the selection of die-attach materials, package types, bonding techniques, via designs, etc. External thermal management considers the selection of cooling modes, heat sinks, attachment processes, etc. Convective thermal resistances for various coolants and cooling modes can range from 100°C W−1 for natural air convection to 33°C W−1 for forced air convection to 1°C W−1 for forced fluorochemical liquid convection. Heat sinks can reduce external thermal resistance to under 15°C W−1 in natural convection and as low as 5°C W−1 for moderate forced convection. Liquid cooled heat sinks can reduce the resistance to 1°C W−1 or lower. After the coolant and cooling mode are determined, the thermal system needs to be designed in detail.
How is thermal resistance measured?
Thermal resistance can be measured by performing heating and cooling experiments on industrial dies or laboratory model dies. These experiments involve comparing the measured temperatures at different surface locations of a die against the calculated temperatures. This comparison is done with the help of physical properties such as density, thermal conductivity, heat capacity, and emissivity of the die material. Typical values of emissivity for HRCS and ceramic dies are 0.82 and 0.5 respectively, while the convective heat exchange coefficient h is usually set at 5 W/m2/K. The ambient temperature may either be 900°C in a press furnace or 25°C outside during blank removal.
To measure thermal resistance, the various sections of the thermal path must first be determined. These include the chip-to-package, package-to-heat sink and heat sink-to-inside ambient, and inside-to-outside ambient. The internal thermal management should also be considered, and includes the selection of die-attach materials, package types, bonding techniques, and via designs. Once all these have been determined, heating and cooling experiments can be performed on the industrial or laboratory die, and the temperatures at different surface locations can be compared to the calculated temperatures. This comparison will help determine the overall thermal resistance of the die.
How is heat dissipation managed?
Heat dissipation is managed by first defining the boundary conditions such as the maximum power dissipation of major chips, the power levels of the hard disk drives, power supplies, video cards, and PCMCIA slots, as well as ambient temperatures. The next step is the thermal budgeting of the complete thermal solution. This involves distributing the total thermal resistance from the junction to the ambient among various areas such as chip-to-package, package-to-heat sink, and heat sink-to-inside and outside ambient.
In order to increase the wetted area for heat transfer and reduce the external thermal resistance, heat sinks can be used. For a wetted area of 10 cm2, the external thermal resistance can be reduced from 100°C W−1 for natural air convection to 33°C W−1 for forced air convection and to 1°C W−1 for forced fluorochemical liquid convection. Heat sinks can reduce the external thermal resistance to under 15°C W−1 in natural convection and as low as 5°C W−1 for moderate forced convection. Liquid cooled heat sinks can further reduce the resistance to 1°C W−1 or lower.
Once the coolant and the cooling mode are determined, the thermal system has to be designed in detail, including the selection of die-attach materials, package types, bonding techniques, via designs, selection of the cooling modes and heat sinks, and attachment processes. Finally, a thermal model is created to calculate the overall heat management of the system. This simulation can be used to determine the arrangement of cells in the module and the necessary cooling measures before prototyping starts.
What is the role of convection in thermal design?
Convection plays an important role in thermal design. Convection is the transfer of heat energy through the physical movement of a fluid, usually air or liquid. In thermal design, convective thermal resistance is used to measure the total thermal resistance from junction to ambient. This resistance is distributed among various sections of the thermal path such as the chip-to-package, package-to-heat sink, and heat sink-to-inside ambient. The convective heat transfer coefficient and the wetted area are also taken into account. For a given wetted area, the external thermal resistances range from 100°C W−1 for natural air convection to 1°C W−1 for forced fluorochemical liquid convection. Heat sinks can also be used to increase the wetted area and reduce the external thermal resistance. Air-cooled heat sinks can reduce the external thermal resistance to under 15°C W−1 in natural convection and as low as 5°C W−1 for moderate forced convection. Liquid cooled heat sinks can reduce the resistance to 1°C W−1 or lower.
What tools are used for thermal design modelling?
Tools used for thermal design modelling include the Thermal Wizard for product specification, SolidWorks for CAD drawing, and simulation tools such as radiator, fluid and strength calculations. Additionally, ElectroMagnetic Compatibility (EMC) testing is performed both in-house and at external partners. As part of the design process, temperature set points are adjusted in order to reduce temperature variation and optimize the average tool surface temperature. A variety of computer-aided engineering tools, such as finite element analysis (FEA), computational fluid dynamics (CFD), and thermal imaging, can be used to verify and validate the design.
What is the role of thermal conductance matrix in thermal design?
The thermal conductance matrix (K) is an essential part of the thermal design process, as it describes the heat transfer between elements in the 3 Cartesian axes. This matrix is derived by summing the individual thermal conductances of all the paths connected to each element, considering the appropriate boundary conditions. The conductance coefficient (k’) is a measure of the effectiveness of an interface between two solid surfaces to transmit heat, and is used to calculate the thermal resistance across a boundary with an area A. With the thermal conductance matrix, the rate of temperature change of each element is described by the balance of the heat stored, generated, and net heat flow in or out of the element. This ensures that the thermal design process accounts for all the heat transfer paths in the system and accurately models the temperature distribution in the system.
How does thermal energy affect hardware designs?
Thermal energy plays a key role in the design of hardware for electronic components. The maximum power dissipation of major chips, such as CPUs and GPUs, as well as the power levels of hard disk drives, power supplies, video cards and PCMCIA slots must all be taken into consideration when designing effective thermal solutions. In addition, ambient temperature must be taken into account, as electronic systems may be subjected to extreme temperature environments.
The design of the thermal system must then begin in earnest, with engineers determining the necessary convective thermal resistances and wetted areas for various coolants and cooling modes. Often, heat sinks are used to increase the wetted area for heat transfer and reduce the external thermal resistance to a more manageable level, as can liquid cooling.
Ultimately, thermal energy is a crucial consideration for hardware design, as it impacts all aspects of the design process from internal thermal management schemes to external thermal management schemes, from convective thermal resistances to wetted areas, from coolants and cooling modes to heat sinks. Without a proper understanding and consideration of thermal energy, hardware designs could be severely hampered or rendered ineffective.
What are the considerations for thermal design in spacecraft? When it comes to thermal design in spacecraft, there are several considerations that must be taken into account. On the mechanical side, the primary considerations are dynamic and static structural loading experienced during launch. On the thermal side, the considerations include component temperature ratings and worst-case hot/cold states of the spacecraft, which is driven by thermal dissipation of electronics and the dynamic thermal radiation environment on-orbit. It is important to note that the relative simplicity and compact nature of small satellites results in a close coupling between mechanical and thermal design, both at the spacecraft and subsystem-levels. As a thermal engineer at JPL, one must investigate, plan, design and develop mechanical products and systems such as spacecraft, instruments, robots, packaged electronics, controls, engines, and machines, and mechanical, thermal, hydraulic, propulsion, or heat transfer systems for the production, transmission, measurement, and use of energy. This includes designing hardware and control systems to manage system temperatures within safe operating ranges through the use of radiation, conduction, convection, single- and two-phase heat transfer methods, as well as conducting trade studies and establishing thermal requirements, hardware specifications, and installation instructions.