Engenharia Mecânica
URI Permanente desta comunidade
Navegar
Navegando Engenharia Mecânica por Título
Agora exibindo 1 - 20 de 631
Resultados por página
Opções de Ordenação
Artigo 3D computer tomography for measurement of femoral position in acl reconstruction(2015) FERNANDES, TIAGO LAZZARETTI; MARTINS, N. M. M. F.; WATAI, F. A.; ALBUQUERQUE, Cyro; PEDRINELLI, A.; HERNANDEZ, A. J.Artigo de revisão A CFD analysis of the flow dynamics of a directly-operated safety relief valve(2018) Scuro N.L.; Angelo E.; Angelo G.; Andrade D.A.© 2018 Elsevier B.V.A three-dimensional numerical study on steady state was designed for a safety relief valve using several openings and inlet pressures. The ANSYS-CFX® commercial code was used as a CFD tool to obtain several properties using dry saturated steam revised by IAPWS-IF97. Mass flow and discharge coefficient calculated from simulations are compared to the ASME 2011a Section 1 standard. The model presented constant behavior for opening lifts smaller than 12 mm and is very reasonable when compared to the standard (ASME). In addition, the conventional procedure to design normal disc force assumes that all the fluid mechanical energy was converted into work; however, the CFD simulations showed that average normal disc force is about 19% lower than theoretical ASME force, which could prevent the valve oversizing. A numerical validation was conducted for a transonic air flow through a converging–diverging diffuser geometry to verify the solver's ability to capture the position and intensity of a shockwave: the results showed good agreement with the benchmark experiments.Artigo de evento A comparison of different assistance strategies in power assisted wheelchairs using an optimal control formulation(2016-08-18) CUERVA, V. I.; Marko Ackermann; Fabrizio LeonardiPower assisted wheelchairs are a promising solution to overcome problems associated with manual wheelchair propulsion, such as the incidence of upper limbs injuries and muscle fatigue. However, there are still open questions regarding the most appropriate assistance strategy. The main goal of this paper is to compare three different types of assistance in power assisted wheelchairs: constant force, proportional force and a novel type of assistance inspired on the impedance control theory. The comparison was performed using a simple model and an optimal control formulation that searched for optimal user actuation and controller parameters so as to minimize the user effort. The fairness of the comparison was ensured by imposing an upper bound on the energy consumption by the motors. The results show that the proportional and impedance controlbased strategies are the most appropriate steady state conditions. In typical daily activities such as obstacle avoidance, the impedance control has advantage as it permits a faster system's response.Artigo de evento A computational study of the swing phase of the gait with standard and spring-loaded crutches(2012-06-12) Marko Ackermann; TAISSUN, B. A.Crutches have suffered few functional modifications over their long history, with improvements largely limited to aesthetics and weight reduction aspects. The large energetic cost of the gait with crutches and problems associated to their long-term use impose a heavy burden to the users. In order to mitigate some of the mentioned problems, alternative designs have been proposed over the past few decades. Among them, the idea of incorporating an elastic element to the crutches to reduce impact forces transmitted to the upper extremities and to promote energy storage and release has been indicated in the specialized literature as a potential solution, in particular for the crutch gait styles more similar to the normative human gait such as the two-point and the swing-through. In fact, tendon elasticity has been shown to reduce energy consumption during animal and human locomotion by means of energy storage in the initial and mid stance-phase and release in the push-off phase of the gait cycle. In spite of the great potential of this idea, appropriate stiffness curves for the elastic element are poorly studied in the literature. This study aims at investigating appropriate stiffness values for the elastic element of spring-loaded crutches by means of computational simulations using a model of the swing phase of the swing-through gait style. The findings show that the stiffness should be tuned carefully to ensure improved gait quality. Spring-loaded crutches undoubtedly reduce impact forces transmitted to upper limbs and shoulder at touch down but they can deteriorate performance with respect to foot clearance and effort at the shoulder when compared to stiff crutches if stiffness is not carefully selected. © 2012 IEEE.Artigo A low-cost anthropometric walking robot for reproducing gait lab data(2008-12-05) Da Silva Santana R.E.; De Toledo Fleury A.; Menegaldo L.L.Human gait analysis is one of the resources that may be used in the study and treatment of pathologies of the locomotive system. This paper deals with the modelling and control aspects of the design, construction and testing of a biped walking robot conceived to, in limited extents, reproduce the human gait. Robot dimensions have been chosen in order to guarantee anthropomorphic proportions and then to help health professionals in gait studies. The robot has been assembled with low-cost components and can reproduce, in an assisted way, real-gait patterns generated from data previously acquired in gait laboratories. Part of the simulated and experimental results are addressed to demonstrate the ability of the biped robot in reproducing normal and pathological human gait.Artigo de evento A method to simulate motor control strategies to recover from perturbations: Application to a stumble recovery during gait(2011-09-03) FORNER-CORDERO, A.; Marko Ackermann; DE LIMA FREITAS, M.Perturbations during human gait such as a trip or a slip can result in a fall, especially among frail populations such as the elderly. In order to recover from a trip or a stumble during gait, humans perform different types of recovery strategies. It is very useful to uncover the mechanisms of the recovery to improve training methods for populations at risk of falling. Moreover, human recovery strategies could be applied to implement controllers for bipedal robot walker, as an application of biomimetic design. A biomechanical model of the response to a trip during gait might uncover the control mechanisms underlying the different recovery strategies and the adaptation of the responses found during the execution of successive perturbation trials. This paper introduces a model of stumble in the multibody system framework. This model is used to assess different feedforward strategies to recover from a trip. First of all, normal gait patterns for the musculoskeletal system model are obtained by solving an optimal control problem. Secondly, the reference gait is perturbed by the application of forces on the swinging foot in different ways: as an instantaneous inelastic collision of the foot with an obstacle, as an impulsive horizontal force or using a force curve measured experimentally during gait perturbation experiments. The influence of the type of perturbation, the timing of the collision with respect to the gait cycle, as well as of the coefficient of restitution was investigated previously. Finally, in order to test the effects of different muscle excitation levels on the initial phases of the recovery response, several muscle excitations were added to selected muscles of the legs, thus providing a simulation of the recovery reactions. These results pave the way for future analysis and modeling of the control mechanisms of gait. © 2011 IEEE.Artigo de evento A modeling framework to investigate the radial component of the pushrim force in manual wheelchair propulsion(2015-11-25) Marko Ackermann; COSTA, H. R.; Fabrizio Leonardi© Owned by the authors, published by EDP Sciences, 2015.The ratio of tangential to total pushrim force, the so-called Fraction Effective Force (FEF), has been used to evaluate wheelchair propulsion efficiency based on the fact that only the tangential component of the force on the pushrim contributes to actual wheelchair propulsion. Experimental studies, however, consistently show low FEF values and recent experimental as well as modelling investigations have conclusively shown that a more tangential pushrim force direction can lead to a decrease and not increase in propulsion efficiency. This study aims at quantifying the contributions of active, inertial and gravitational forces to the normal pushrim component. In order to achieve this goal, an inverse dynamics-based framework is proposed to estimate individual contributions to the pushrim forces using a model of the wheelchair-user system. The results show that the radial pushrim force component arise to a great extent due to purely mechanical effects, including inertial and gravitational forces. These results corroborate previous findings according to which radial pushrim force components are not necessarily a result of inefficient propulsion strategies or hand-rim friction requirements. This study proposes a novel framework to quantify the individual contributions of active, inertial and gravitational forces to pushrim forces during wheelchair propulsion.Artigo de evento A novel scroll expander for flank leakage investigation: preliminary tests(2016-07-19) FANTI, G. R.; Gustavo Donato; Paulo de Mello© 2016 University of Ljubljana.The isentropic efficiency of the expander is a concern for organic Rankine cycle (ORC) and compressed air energy storage (CAES) implementation. In these applications, the expander alone has a great influence over the whole system efficiency. Scroll expanders are particularly interesting for the low power range comprehended between 1 and 10 kW. Many previous works have attributed to internal leakages a great importance to obtain high isentropic efficiency in these machines. We present herein experimental results obtained with a novel scroll expander constructed to investigate the effect of internal leakages. We discuss the geometry definition and design of the prototype in detail. The maximum mechanical power produced by the prototype was 923 W at 2690 rpm but its isentropic efficiency was only 30.6%. Filling factor as high as 4.9 reveals that internal leakage must be reduced to obtain a more efficient expander.Artigo de evento A study of a solar chimney to improve comfort inside shipping containers(2014-06-15) MALTA, F. P.; GOUVEIA, J. L. F.; Cyro AlbuquerqueShipping container is a cheap and easy way to build an internal environment. If occupied by people in warm climates, thermal discomfort usually occurs. The aim of this work is to investigate the use of solar chimney for natural ventilation inside containers. The cavity of the chimney, with trapezoidal cross section, is formed by placing a thermal insulating material against the lateral wall. The air enters the cavity from the internal environment through the bottom, flows to the top due to the heating of the metallic wall, and is dispersed in the external environment. An experimental apparatus was built with one cavity of a real container. The metallic wall was heated by electric heaters, in a range representative of solar incidence. Sensors of temperature and air velocity were positioned along the chimney. It was found that the chimney works even for low solar incidence. In the center between the metallic wall and the insulation, the air velocity is higher and the temperature is lower than near the walls. The effect of the radiative heat transfer from the metallic wall to the insulation significantly influences the temperature and the velocity profile.Artigo A study on friction coefficient and wear coefficient of coated systems submitted to micro-scale abrasion tests(2013) Cozza R.C.Several works on friction coefficient during abrasive wear tests are available in the literature, but only a few were dedicated to the friction coefficient in micro-abrasive wear tests conducted with rotating ball. This work aims to study the influence of titanium nitride (TiN) and titanium carbide (TiC) coating hardness on the friction coefficient and wear coefficient in ball-cratering micro-abrasive wear tests. A ball of AISI 52100 steel and two specimens of AISI D2 tool steel, one coated with TiN and another coated with TiC, were used in the experiments. The abrasive slurry was prepared with black silicon carbide (SiC) particles and distilled water. Two normal forces and six sliding distances were defined, and both normal and tangential forces were monitored constantly during all tests. The movement of the specimen in the direction parallel to the applied force was also constantly monitored with the help of an electronic linear ruler. This procedure allowed the calculation of crater geometry, and thus the wear coefficient for the different sliding distances without the need to stop the test. The friction coefficient was determined by the ratio between the tangential and the normal forces, and for both TiN and TiC coatings, the values remained, approximately, in the same range (from μ= 0.4 to μ= 0.9). On the other hand, the wear coefficient decreased with the increase in coating hardness. © 2012 Elsevier B.V.Artigo A transient three-dimensional heat transfer model of the human body(2009-08-05) FERREIRA, M. S.; YANAGIHARA, J. I.The objective of this work is to develop an improved model of the human thermal system. The features included are important to solve real problems: 3D heat conduction, the use of elliptical cylinders to adequately approximate body geometry, the careful representation of tissues and important organs, and the flexibility of the computational implementation. Focus is on the passive system, which is composed by 15 cylindrical elements and it includes heat transfer between large arteries and veins. The results of thermal neutrality and transient simulations are in excellent agreement with experimental data, indicating that the model represents adequately the behavior of the human thermal system. © 2009 Elsevier Ltd. All rights reserved.Dissertação Adoção da tecnologia da informação em saúde sob a perspectiva do custo efetividade(2019) Gonçalves, M. J.O progresso em tecnologias da informação em saúde oferece novas oportunidades, bem como novos cenários de aplicação, trazendo benefícios em qualidade dos serviços médicos e redução dos custos de saúde. As organizações de saúde, consideram a aplicação da Tecnologia da Informação como uma chave fundamental para melhorar a gestão de saúde, porém poucos trabalhos analisam o impacto de sistemas de informação em termos econômicos e de qualidade dos cuidados aos pacientes, além da escassez de estudos que considerarem as características da tecnologia da informação em saúde e as relações que vinculam a informação ao seu ambiente para tomada de decisão. A literatura relacionada com a Avaliação da Tecnologia da Informação em saúde parece ser ainda muito dispersa e fragmentada, demandando novos estudos. Assim, o objetivo geral deste trabalho consiste em propor um framework de avaliação de tecnologia da informação em saúde na perspectiva do custo efetividade, combinando diferentes modelos de adoção de tecnologia. A pesquisa buscou preencher a lacuna e examinar um modelo de avaliação abrangente e documentar o seu impacto sobre o processo decisório dos hospitais em adotar tecnologias em saúde e de fato alavancar resultados tanto para o paciente como uma forma de melhorar a gestão. Para o desenvolvimento do estudo foi aplicado o método Design Science Research (DSR) e avaliação do framework foi feito através de três estudos de caso realizados em hospitais público e público-privado. Os resultados indicam que a avaliação da tecnologia em saúde demanda um framework abrangente, sendo necessário abordar problemas de tecnologia, humanos, organização e aspecto econômico (custo-efetividade).Artigo Adoção de materiais resistentes ao desgaste em projetos industriais(2015) COZZA, Ronaldo Câmara; RODRIGUES, Lucas Cremonese; SCHON, Cláudio GeraldoArtigo Adressing Energy Demand and Climate Change through the Second Law of Thermodynamics and LCA towards a Rational Use of Energy in Brazilian Households(2022-10-25) PEREIRA, M. T. R. M.; CARVALHO, M.; Carlos Mady© 2022 by the authors.This study focuses on a typical Brazilian household through the lens of sustainable development, regarding energy demand and GHG emissions. The analysis encompasses both the direct and indirect energy, exergy consumption, and GHG emissions (quantified by life cycle assessment) associated with the usual routine of a household. The household is modeled as a thermodynamic system to evaluate inputs (food, electricity, fuels for transportation) and outputs (solid and liquid residues). The hypothesis is that each input and output contains CO (Formula presented.) emissions and exergy derived from its physical-chemical characteristics or production chains. Each household appliance is modeled and tested as a function of external parameters. The contribution of several industries was obtained to the total GHG emissions and exergy flows entering and exiting the household (e.g., fuels for transportation, food, gas, electricity, wastewater treatment, solid waste). It was verified that urban transportation was the flow with the highest GHG and exergy intensity, ranging between 1.49 and 7.53 kgCO (Formula presented.) /day and achieving 94.7 MJ/day, almost five times higher than the calculated exergy demand due to electricity. The second largest flow in GHG emissions was food due to the characteristics of the production chains, ranging from 1.6 to 4.75 kgCO (Formula presented.) /day, depending on the adopted diet. On the other hand, the electricity presented low GHG emissions due to the main energy sources used to generate electricity, only 0.52 kgCO (Formula presented.) /day. Moreover, the chemical exergy of the solid waste was 9.7 MJ/day, and is not irrelevant compared to the other flows, representing an interesting improvement opportunity as it is entirely wasted in the baseline scenario.Artigo de evento Advanced multi-metallic SOFC anode development by mechanical alloying route(2010-01-05) TESTIVO, T. A. G.; LEITE, D. W.; MELLO-CASTANHO, S. R. W.Anodes composed of Ni-YSZ (yttria-stabilised zirconia) cermets are the key material to allow direct biofuel feeding to Solid Oxide Fuel Cell (SOFC) devices due to its internal reforming capability. The main challenge among these materials is related to carbon deposition poisoning effect when C-bearing fuels are feed. The work deals with these issues by alloying Ni with some metals like Cu to conform a multi-metallic anode material. Mechanical alloying (MA) at shaker mills is chosen as the route to incorporate the metal and ceramic powders in the anode material, also leading to better sintering behaviour. A projected cermet material is conceived where a third metal can be added based on two criteria: low Cu solubility and similar formation enthalpy of hydrides regarding Ni. Refractory metals like Nb, W and Mo, seems to fulfil these characteristics, as well as Ag. The MA resulted powder morphology is highly homogeneous showing nanometric interpolated metal lamellae. The sintering behaviour is investigated by conventional dilatometry as well as by stepwise isothermal dilatometry (SID) quasi-isothermal method to determine the sintering kinetic parameters. Based on these tools, it is found the Cu additive promotes sintering to obtain a denser anode and therefore allowing lower process temperatures. The consolidation is achieved through the sintering by activated surface (SAS) method allied to liquid phase sintering process, where the third metal additive also has influenced. The final cermet can be obtained at one sole process step, dispensing pore-forming additives and reduction treatments. The sintered microstructure demonstrates the material is homogeneous and possesses suitable percolation networks and pore structure for SOFC anode applications. © (2010) Trans Tech Publications.Trabalho de Conclusão de Curso AGRO ATON(2021-06-16) Buonaccorsi, Gabriel Oliveira; Seixas, Gabriel Peters; Conzatti, Giovani Bruno; Almeida, Luis Henrique Pereira; Freire, Luiz Felipe; Leonardi, Pedro Augusto; Scarparo, Pedro Targa; Reis, Vitor Paino BeltrameO plantio de alho no Brasil é realizado muitas vezes de forma manual por falta de um implemento que seja acessível ao pequeno/médio produtor. O plantio manual garante um bom resultado, devido ao fácil manuseio e posicionamento do bulbilho de alho no solo. Porém, um alto consumo de tempo é requerido para essa forma de plantio, o que acaba por encarecer o produto. Após um estudo apurado sobre o tema foi constatado que a fase crucial de todo o processo é o posicionamento de forma correta do alho-semente (bulbilho) na fase de plantio, fundamental para um pleno desenvolvimento vegetativo. O projeto tem como objetivo a criação e modelagem em software de um implemento para auxílio ao plantio do alho com a utilização de um trator de pequeno porte, que envolve todo o processo de deposição dos bulbilhos no solo por meio de um sistema mecanizado a fim de otimizar e aumentar a rentabilidade de sua produção visando as necessidades do pequeno produtor.Com isso, além de todo o processo automático, existe a grande possibilidade de se minimizar tempo no processo e ganha-se em custo operacional.Dissertação Ambiente de otimização dinâmica e simulação para obtenção de perfis de velocidade ótimos de veículos pesados com calibração simplificada(2023) Barbosa, Pedro MunizUma quantidade significativa de combustível fóssil consumido e poluentes emitidos em todo o mundo pode ser atrelada ao transporte em modal rodoviário. Além disso, o combustível sempre foi uma das principais parcelas em relação à precificação dos transportes de cargas e com isso, a economia dele se tornou um dos pilares para o desenvolvimento de novas tecnologias veiculares. A ecocondução, que consiste em conduzir o veículo visando condições de alta eficiência energética, tem sido amplamente estudada nos últimos anos devido aos seus possíveis benefícios na redução do consumo de combustível e emissão de poluentes. Uma das frentes de estudo da ecocondução é a otimização de perfis de velocidade, que se traduz em, através de um problema de controle ótimo, minimizar o consumo de combustível de uma rota tendo como variável de controle a velocidade do veículo. Boa parte das montadoras de veículos pesados já possuem soluções que buscam economizar combustível através desta estratégia, porém, tais soluções só são introduzidas no mercado através de veículos novos. Devido à alta idade média dos veículos rodoviários no Brasil e ao constante aumento dela, métodos que sejam também aplicáveis para esta frota já existente poderiam auxiliar no aumento da eficiência energética dela mais rapidamente. Neste trabalho é proposto um ambiente computacional baseado em otimização dinâmica e simulação numérica rigorosa para minimização do consumo de combustível em veículos pesados, através da otimização de perfis de velocidade em trajetos rodoviários que seja de aplicação genérica, ou seja, aplicável em qualquer marca ou modelo de veículo e que não necessite em sua calibração dados altamente custosos a serem obtidos, como fazem as soluções já existentes disponibilizadas por algumas montadoras. A metodologia utilizada consiste em definir um modelo de consumo de combustível de elevada exatidão e de fácil calibração, um modelo de dinâmica veicular que abrange os principais parâmetros de movimento do veículo, elaborar e resolver o problema de controle ótimo e por fim, verificar o desempenho da solução em um ambiente de simulação dinâmica que aborda diversos aspectos dimensionais e cinemáticos do veículo e do trajeto através do programa TruckSim. Os resultados mostraram, nos cenários de estudo, que tal solução tem capacidade de reduzir 8,32% em média do consumo de combustível de um caminhão quando comparado a um perfil de velocidade constanteTrabalho de Conclusão de Curso AMORPH : Suspensão MacPherson com cambagem sob demanda(2021-06-18) Bragagnolo, Carolina Padilha; Minatogawa Junior, Edson Akira; Almeida, Gabriel Paulino de; Alves, Henrique Marques; Gili, Jordão Queiroz; Barreto, Lucas Botelho; Correa, Marcelo de Camargo; Callegaris, Rodrigo; Guedes, Vitor SencadesA crescente busca por esportividade pode gerar um resultado catastrófico se não efetuadade forma coerente e responsável, aumentando o número de acidentes tanto em autódromos, quanto em rodovias, onde é possível desenvolver alta velocidadee uma aceleraçãolateral mais próxima do limite suportado pelos pneus. Partindo-se de uma análise de mercado, para se atender uma necessidade específica, este trabalho de conclusão de curso explora a conceituação, design, concepção e simulação de um sistema capaz de aproveitar o máximo potencial da dinâmica lateral de um veículo, através da alteração da cambagem do eixo dianteiro para uma condição adequada a situação veicular, por isso, sob demanda.A base para o desenvolvimento se deu através doestudo dos gradientes de subesterçamento propostos por Gillespie, em especial, do Kcamber. Este gradiente atua como um remediador do erro de trajetória, diminuindo o substerço do veículo, quando se aplica cambagem negativa. Aatuação se dá por meio de um motor elétrico e um sistema pinhão-cremalheira, fixados aos braços inferiorese ao pivô da suspensão. A movimentação da cremalheira produz uma variação no comprimento do braço e então produz a alteração da cambagem. Escolheu-se a suspensão do tipo MacPhersonpor estar presente em 80% dos carros produzidos em todo o mundo. Ao longodo desenvolvimento foram utilizadas ferramentas de Engenharia tais como Matriz de Decisão, Boundary Diagram, P-Diagram, FASTe FMEApara nortear as decisões. Tal variação também é capaz de otimizar o contato pneu-solo e o desgaste desuniforme, já que a cambagem só será aplicada em curvas. Por meio de simulações no software CarSim, verificou-se uma redução de até 20,86%da rolagem de carroceria, o que garante um maior controle do veículoe, uma redução de 27,3% do erro de trajetória, o que evidencia uma situação veicular mais próxima da neutra. Em contrapartida, a implementação do sistema traz de renúncia 26,26 kg agregados à massa não suspensa do eixo dianteiro do veículo o que afeta diretamente a frequência de oscilação dessa massa, de 13 para 10 Hz, sugerindo que talvez seja necessário também readequar a rigidez das molas do conjunto dianteiro. Do ponto de vista do design, o pacote disponível para o desenvolvimento foi devidamente aproveitado e as soluções apresentadas tem capacidade de suportar os esforços já que também foi feita a verificação por elementos finitos. Por fim, o projeto apresenta uma tendencia inovadora e com uma expectativa de custo próxima ao que se obtém em preparações veiculares bem elaboradas.Artigo An integrated model of the thermoregulatory and respiratory systems of the human body(2020-07-05) Cyro Albuquerque; YANAGIHARA, J.I.This work aims to develop a mathematical model for computing the distribution of temperature, O2, and CO2 in the human body, depending on the ambient conditions. The body is divided into segments, including layers of tissues and blood compartments, where mass and energy balances are applied. The inclusion of O2 and CO2 transfer mechanisms throughout all segments and tissues of the human body is one of the great novelties of this work. It also includes the exothermic metabolic reactions in the tissues, the transportation of O2 and CO2 by the blood, and the energy exchanged with the environment through the skin and by ventilation. The model also includes the regulation of metabolism, circulation, ventilation, and sweating, depending on the body temperature and the concentrations of O2 and CO2 in the blood. The lungs are represented by alveolar and blood compartments, with diffusion between them. Comparisons with experimental data from the existing literature show that the proposed model is suitable for representing transient exposure to cold and warm ambient temperatures, low concentration of O2, and high concentrations of CO2. In the end, some results demonstrate the effect of ambient temperature on the distribution of temperature, O2, and CO2 across segments, blood, and tissues. Shivering in a cold environment reduces the concentration of O2 and increases the concentration of CO2 in the muscles, which results in increased ventilation and blood circulation. The concentration of gases in the skin depends mainly on variations in the skin's circulation with the environment, which alters the availability of O2 and the elimination of CO2. Small variations were found in the concentrations of O2 and CO2 in the brain and lungs.Artigo An integrated model of the thermoregulatory and respiratory systems of the human body(2020-07-05) YANAGIHARA, J. I.© 2020 Elsevier LtdThis work aims to develop a mathematical model for computing the distribution of temperature, O2, and CO2 in the human body, depending on the ambient conditions. The body is divided into segments, including layers of tissues and blood compartments, where mass and energy balances are applied. The inclusion of O2 and CO2 transfer mechanisms throughout all segments and tissues of the human body is one of the great novelties of this work. It also includes the exothermic metabolic reactions in the tissues, the transportation of O2 and CO2 by the blood, and the energy exchanged with the environment through the skin and by ventilation. The model also includes the regulation of metabolism, circulation, ventilation, and sweating, depending on the body temperature and the concentrations of O2 and CO2 in the blood. The lungs are represented by alveolar and blood compartments, with diffusion between them. Comparisons with experimental data from the existing literature show that the proposed model is suitable for representing transient exposure to cold and warm ambient temperatures, low concentration of O2, and high concentrations of CO2. In the end, some results demonstrate the effect of ambient temperature on the distribution of temperature, O2, and CO2 across segments, blood, and tissues. Shivering in a cold environment reduces the concentration of O2 and increases the concentration of CO2 in the muscles, which results in increased ventilation and blood circulation. The concentration of gases in the skin depends mainly on variations in the skin's circulation with the environment, which alters the availability of O2 and the elimination of CO2. Small variations were found in the concentrations of O2 and CO2 in the brain and lungs.