Authored by Esra Taştan Özkan*
Abstract
Thermal manikins are devices used especially for heat and moisture transfer measurements due to their human form shape and their ability to sweat and move. Thermal manikins generally work in uniform form and at constant surface temperatures representing skin temperature near neutral. The main aim of this work was to investigate the types of thermal manikins and their properties and to talk about the works done using thermal manikins from the past to the present. As a result, thermal manikin systems give better results than wear trials, especially in the measurement of sportswear due to the sweating and movement functions of the systems.
Keywords: Water vapor resistance; Thermal resistance; Thermal manikins; Standards
Introduction
The thermal manikin is one of the tools used to evaluate the thermal comfort of the garment and layered clothing systems. Thermal manikins for measuring thermal properties of garments, compared to other methods allow the investigation of multidimensional garments.
Thermal manikins are a widely used device for thermal resistance and evaporation resistance measurements in clothes, as they give precise results as well as repeatability and ease of tests. The first thermal manikins were produced by the US military in the early 1940s. Later, thermal manikins with different body parts, inability to sweat and movement abilities were produced. In terms of functionality, thermal manikins can be divided into three different categories. These are: a) immobile and non-sweating thermal manikins b) thermal manikins that cannot move but can sweat c) thermal manikins that can move and sweat. Examples of these are Coppellius produced in Finland and Walter produced in Hong Kong [1]. Some of the researches about this subject were given below:
Fan J, et al. [2] in this study, the thermal manikins and its internal structure are shown (Figure 1). The manikin is hung from the head of a water pipe, which also supplies water to the manikin’s body. The manikin is covered with a layer of water repellent breathable leather and filled with water. In the centre of the body, there is an internal heating system and provides heat to the body, and there is a water circulation system that sends the heat of two pumps and pipes to the head and limbs. The skin is very important because it not only provides sweating but also keeps up to 100 kg of water in the body. For this, a special fabric used in marine applications was provided from Goretex (Figure 2).
Fan J, et al. [3] made a study that gave information about the working principle of the sweating thermal manikin Walter. In the study, the time-dependent change and measurement of water source and water simulating sweating were provided. The results revealed the impact of movement and fit on thermal and evaporation resistance of the garment.
Kuklane K, et al. [4] investigated different shape and size thermal manikins like Lady, Tore and baby manikins. They compared according to 1) tight and loose clothing; (2) serial and parallel calculation models; (3) even and uneven clothing (insulation) distribution; and (4) the effect of wearing clothes. They declared that depending on body shape, the man and female manikins showed different test results (Figure 3).
Elabbassi EB, et al. [5] compared two premature newborn sized manikins according to body heat loss difference. The results showed that heat loss increased with increasing body surface area to body mass ratio. It has also been reported that thermal manikins are more accurate than current mathematical or other measurement techniques for evaluating temperature changes (Figure 4).
Melikov (2004), studied breathing thermal manikins for inside environment measurements. They stated that breathable thermal manikins can be used to judge the thermal comfort and breathing air quality of the passengers in buildings and vehicle cabins to evaluate the thermal comfort and breathing air quality of passengers in buildings and vehicle cabins [6].
Tamura T [7] in this study, a two-layered, mobile, walking, sweating thermal manikin was developed (Figure 5). It consists of the inner part on the manikin body and an outer covering part consisting of 17 parts which are independently controlled by the heat source. The sweating rate of 180 pores in the skin is controlled by peristaltic pumps. The temperature performance of the manikin is examined using thermography (thermal camera).
Celcar D, et al. [8] a thermal manikin named Coppelius was used in this study. This manikin was developed on the basis of Tore, a Swedish dry manikin, and added sweating mechanism. The sweating manikin consists of 18 individually controlled, electrically heated body parts. Due to the 187 individually controlled sweating channels, continuous sweating is realized. The shape of the manikin allows movement in the shoulders, wrists, hips and knees. Figure 6 shows the test environment and the sweat channels of the thermal manikin.
Wang F [9] compared the multi-segment thermal manikin Newton and the one-segment thermal manikin Walter. They declared that in Walter thermal resistance and water vapour resistance can be calculated at once. On the other hand, in Newton that thermal resistance can be measured with dry test or water vapour resistance can be measured with a wet test (Figure 7).
Wang F, et al. [10] coped with the difficulties of adding temperature sensors to the wet skin surface and to measure the evaporation resistance more precisely, a sensitive leather model was developed on the thermal manikin TORE. In this study, wetting of a dry and warmed Tore thermal manikin with perspiration was simulated using a knitted structure that fits snugly on the body. Depending on the assumed skin temperature, an international skin temperature empirical equation has been developed. Wire temperature sensors utilized in the evaluation of the surface temperatures of the naked manikin (Figure 8).
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